The folks in the Tea Parties across America should be prepared to be disappointed after this year's election returns are in. That sounds like a sweeping and Democratically-optimistic election prediction, but it's not. I'm actually assuming here that many Tea Party candidates will indeed win at the polls. Instead, what I'm talking about is what happens afterwards. Because while it's a whole lot of fun to wave signs at a rally, actually governing is a whole different story.

The media has already decided this is "The Year Of The Tea Party," no matter what happens at the polls. Something like 130 candidates have been identified (or identified themselves) as Tea Partiers this year. And, as I said, some of them are going to win their races. Not all of them are named Christine O'Donnell, in other words. And they're going to arrive in Washington next January with the wind at their backs, and raring to go. But that's when things are going to get a little tricky.

The Republican Party, whether it takes over either house of Congress or not, is going to have to deal with the outsiders becoming insiders, and making demands on the party as a whole. This struggle may play out in the media, and then again it may not. Republicans are generally a whole lot better than Democrats about hiding such dirty laundry from the public eye, but the Tea Party folks may not be as disciplined as the party regulars in this regard, so it'll be interesting to see how this plays out.

But while it's tempting to draw conclusions about the Tea Party faction based on the recent struggle in the Democratic Party between party regulars and the Blue Dogs, I don't think many of these lessons are going to apply to the Tea Partiers in the Republican Party -- because it is a completely different dynamic. On the Democratic side, the party's base wanted to accomplish big changes, but the Blue Dog faction was more in favor of (at the most) tiny, incremental changes. And, for the most part, the Blue Dogs won the day, because they knew they had just enough numbers to force the rest of the party to accept their demands. The Blue Dogs weren't powerful enough to actually set the Democratic agenda, but they were powerful enough to water it down when it came to the actual legislation produced.

But the Tea Party dynamic is the reverse of this. The Tea Partiers are the ones demanding big changes, and the Republican Party is likely going to wind up being the dog that gets wagged by the Tea Party tail. Serious-minded Republican Party stalwarts are going to be in an awfully tough position, because they are going to be absolutely terrified of the Tea Party movement. They've seen how easy it is for sitting Republican politicians (or up-and-coming traditional Republican candidates, for that matter) to be trounced in the primaries by fire-breathing Tea Partiers. Which means they're going to live in fear of the same thing happening to them, if they don't go along with the Tea Party agenda. Even though the numbers of Tea Party candidates who win office are likely to be small when compared to the Republican Party as a whole, they are going to be the ones setting the course for the party for the next few years. Which is why, as I said, not many parallels can be drawn with the Blue Dog situation in the Democratic Party.

But when the rubber meets the road legislatively, things are going to get very tough for the new Tea Party politicians. Because they have been out there promising things which are going to be very difficult -- if not downright impossible -- to actually achieve, once they get into office. Which is why the Tea Party voters should be prepared to be disappointed.

If the Tea Partiers had a different agenda, this might not be such a big problem, but at the core of the Tea Party is a giant contradiction that is going to have to be faced once the excitement of the election is over and done with. Stripped of all the "take our country back" rhetoric and patriotic garb, the Tea Party's basic two tenets are mutually exclusive. The Tea Partiers say they stand for (1) lower taxes, and (2) cutting the deficit. But they're going to have to realize (about the time that their first budget proposal comes back from the Congressional Budget Office with some numbers attached to it) that you simply can't do both right now. Even conservative news outlets have all but given up on the fantasy that "tax cuts pay for themselves" (as evidenced by the brutal interview of Carly Fiorina yesterday by Chris Wallace of Fox News Sunday), and are pointing out that extending the Bush tax cuts (for example) is going to raise the deficit by trillions of dollars.

Which means that the Tea Partiers are going to be faced with a very tough choice -- either make good on their promises to bestow lots of tax cuts for all, or make good on the promise of cutting the deficit. And no matter which direction they take, they are going to disappoint a lot of their fans. The Republican Party has been content, up until now, to slash taxes again and again, and to ignore what this has done to the country's deficit and debt (as Dick Cheney famously put it, "deficits don't matter."). But the Tea Partiers are going to be in no mood to see deficit projections actually going up after this election -- which will be all the more pronounced if Republicans actually win the House or the Senate (since, if it happens, they'll be the ones coming up with the budgets in the first place).

Tea Partiers are also going to be in no mood to accept that they can't have their cake and eat it, too. It is going to be unacceptable to the Tea Party rank and file to see either (1) higher taxes, or (2) increased deficits from the people they worked so hard to get elected. But the math, being non-ideological, is going to say what it is going to say -- whether the Tea Partiers like it or not.

Of course, the Tea Partiers have an answer to this conundrum: cut government spending. This is seen as a "trump card" which will allegedly cure all budgetary ills. The only problem with this is, once they get into office, they'll be expected to identify exactly what it is that's going to get cut (which most of them have, so far, been unwilling to publicly state). And this is where they're going to find out that most of the rest of the country is simply not with them. Because to solve our deficit problem in the short term -- even before you make it worse with additional tax cuts -- the federal budget is going to need to not only be cut to the bone, but in several areas actually amputated. The Tea Partiers, at least some of them, are not fazed by this prospect, and are even lining up federal departments they would like to see be completely axed (the Department of Education is a favorite on this list, for some reason).

But again, the problem with doing so is that every federal program has its own constituency. Bureaucracies are notoriously hard to kill, in other words. Oh, sure, you can tinker around the edges (the famous "waste, fraud, and abuse" candidates love to talk about), or cut some bizarre-sounding research projects -- but this is awfully small change when compared to the budget as a whole. And with yearly deficits running at $1.3 trillion currently, that sort of thing is barely going to make a dent in the problem.

So once you've cut a few easy targets, what is next? Cutting the Pentagon's massive budget? Cutting farm subsidies? Cutting the F.B.I. or the Border Patrol? Cutting food safety inspectors? Cutting air traffic controllers or airport security? When faced with the reality of what the federal government actually does, it is easy to see that no matter where you look for savings, a significant portion of the public (and the voters) are not going to easily accept drastic budget cuts. Good luck getting elected in a farm state after slashing farm subsidies, for instance. Granted, for each of these budget targets it will be a somewhat different segment of the voters whose ox gets gored, but the principle remains the same no matter where you look, when wielding the budget-slashing axe.

Of course, the Tea Partiers even have an answer for this, too: cut the favorite target of conservatives -- "entitlements." The only problem with that is that most folks don't call these programs "entitlements" (which is, after all, Washington-speak), most folks call them "my Social Security check." The biggest federal entitlement programs are: Social Security, Medicare, and Medicaid. Medicaid will likely be the first target, since it is designed as a safety net for the poor, meaning it will be first on the Republican chopping block. Poor people don't vote in the same numbers as the middle class or the wealthy, so they're a constituency that can safely be ignored (as the Republican line of thought goes). But the other two are more problematic, because they are programs for older Americans -- and older Americans vote at a higher rate than the rest of the public.

Cutting Social Security benefits is going to be a tough sell, in other words. And even Republicans are almost always careful to put such cuts in terms which specify that "we won't be cutting benefits for people who are already on Social Security or about to retire," in an effort to not freak out the seniors (particularly in Florida, an important state in presidential years). But the problem with this is that it means that even if you are proposing future cuts to Social Security, it's not going to do much in the short term to solve the deficit problem. By taking current benefits off the table, it means that the effect on the budget of any cuts you propose is going to be pushed years down the road. Which does nothing for the deficit in the meantime. Cutting Medicare benefits has the same inherent problem, although Republicans seem much more willing to make immediate cuts to current benefits for Medicare than for Social Security, I've noticed.

This is the core problem for the Tea Partiers. Even if they do manage to take control of the Republican Party's agenda, they're not going to have much immediate effect on the deficit at all unless they propose extremely radical changes -- which are going to be politically dangerous for Republicans to actually get behind. Without slashing the federal government in drastic and politically-unacceptable ways, the deficit in the next two years is still going to be incredibly high -- probably over a trillion dollars both years.

And that's going to disappoint a whole lot of Tea Party voters. Because, much as the Progressives became disillusioned with Barack Obama because things weren't changing fast enough or radically enough, the Tea Partiers strike me as having not much patience in terms of waiting for their agenda to get enacted. Especially after "The Year Of The Tea Party" gets a bunch of them elected. There's going to be a pretty short window for them to produce, and whatever they do actually come up with in the way of a budget is all but guaranteed to seriously disappoint large numbers of the Tea Party base. The same excuses will be trotted out by Washington politicians -- "these things don't happen overnight" and all the rest of it -- but my guess is that the Tea Partiers are not going to be very happy hearing that sort of thing.

It is said that politicians campaign in poetry and govern in prose. In other words, you can say anything you want out on the campaign trail, in as high-flown language as you'd like to use; but once the shouting is all over, it's often very hard (if not impossible) to make good on these promises when confronted with the way Washington actually works. And the more exciting the campaign poetry is, the further the voters' expectations have to fall, once you get in office. So, as friendly advice from someone who has watched disillusionment grow on the Left since Obama got elected, I would caution the Tea Partiers now -- even if you have a great election night and see a bunch of Tea Partiers sweep into Washington, I would prepare to be disappointed on seeing the campaign rhetoric become political reality any time soon.

Cross-posted at The Huffington Post

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-- Chris Weigant