A comprehensive immigration reform bill has been approved by the Senate committee responsible for immigration laws, and the bill will now move to the Senate floor. This is good news for people who want to see immigration reform, obviously, but the bill’s still got quite a ways to go before it reaches President Obama’s desk for his signature. There are, in fact, six more hurdles the bill will likely face, and some of them are dauntingly high.

The next step will take place on the Senate floor. If the Senate approves a bill, the House will likely have both a committee vote and a floor vote on a bill. But nobody expects the House to vote on the Senate bill the first time around, meaning what the two houses pass will be different. This leads to the next hurdle, the conference committee composed of members of the House and Senate. They will have to hammer out some deal, and then both houses get to vote one last time on the finished product. That's a lot of hurdles to clear, and there is no guarantee that any bill will wind up on Obama's desk any time soon.

The politics of immigration reform are already messy, and they're just going to get messier the further along the bill gets. President Obama, obviously, wants to sign a bill as a cornerstone of his second-term legacy. As we saw in the healthcare reform bill, however, this can lead to just "wanting to sign a bill" no matter what the bill contains (or leaves out). So far, Obama's talked pretty tough about what he will and will not accept in the bill, but it remains to be seen what compromises he'll agree to during the process.

Republicans don't just want a bill, they absolutely need a bill. The smarter Republicans realize this, which is why we've even gotten this far already. Realistically, Democrats have won five out of the last six popular votes for president, and Republicans know that to have any sort of viable national candidate in the near future, they've got to repair the damage they've done to their own image among Latinos. Countering this realistic and pragmatic view is a large segment of the GOP base, as well as plenty of members of Congress, who will not accept any immigration idea whatsoever, except maybe "send them all home tomorrow!" This party split is going to get wider and deeper when the House begins to act on immigration.

Democrats really want a comprehensive immigration bill, because they actually want to see the goal achieved. However, Democrats are going to have to accept some compromises which pit them against other Democratic aims (more on this in a minute). This will first be tested on the Senate floor, as amendments are added by both sides. And it will really be tested both in the House and in the inevitable conference committee, where the real wheeling and dealing may happen.

So far, the big wedge issue on the Democratic side has come from within. Should gay immigrants be able to sponsor their spouses, if they are married? Well, if you're a Democrat, that probably sounds fine to you. But the Republicans have stated that they'll pull their support for the whole bill, meaning the entire process would die right there on the Senate floor. This forces Democrats into a calculation: is a comprehensive immigration bill which will help millions worth leaving tens of thousands of gay spouses out in the cold? Or, to put it another way: is a "pure" bill that will not pass better than a flawed bill which can be fixed later, but which could actually pass? Is no bill at all better than what we have now?

Gay rights activists are not going to be happy, but the answer is already that they're going to have to wait awhile longer. Gay spouses will not be in the final bill. Democrats have now maneuvered things so that every Democratic senator can vote for gay marriage to be included, but it will not pass a filibuster vote. This way, they won't have to go on record voting against such a thing, but it will not be included in the bill. They could have brought the amendment up in committee, where a few Democrats would have had to vote against it to kill it, but they did not do so. Now they can allow Patrick Leahy to bring the amendment up on the floor, knowing it will fail.

If this sounds like crass politics, well, that's because it is. But again, the choice is between a bill with gay spouses included which will fail and a bill which excludes them which might pass. Gay spouses can push for a separate bill later, especially if their position is strengthened by a Supreme Court ruling on the Defense Of Marriage Act (which will happen in a few months). Politically, waiting might improve their chances, even though it's tough to accept right now.

The wedges the Republicans will try to drive into the bill will be sneakier in nature, for the most part. The GOP knows it needs this bill, but they're not very excited about the bill's goals (to put it mildly). Therefore they may at some point decide "we've done enough to improve our image" and allow the bill to die in some fashion or another. They'll really try to pin the bill's failure (should this happen) on the Democrats, but nobody outside their base is going to believe this. Failure in any form isn't going to convince any Latinos to vote Republican, no matter what congressional Republicans choose to believe.

I have no idea what the prospects for eventual success of any bill are, at this moment. They got a bit better by successfully moving the bill to the Senate floor. After all the fur flies during the Senate floor debate, the real measure of the ultimate chance of the bill becoming law will be the final Senate vote. The bill will likely get at least 60 votes, if it hasn't been gutted too badly in the amendment process. The real question is whether the bill actually gets 70 or 75 or even 80 votes. This may sound impossibly optimistic, but politicians know their constituents may not follow every twist and turn of the debate -- but that they do indeed pay attention to the final vote. So there may be a lot of late movement in support of the bill from Republicans who want to do the right thing for their party's chances in the future on the national stage.

The House will likely dither and grandstand for a while, and they will likely pass some sort of laughably-inadequate bill which makes the path to citizenship absolutely impossible -- perhaps by stating that nobody gets to set foot on that path until the southern border fence reaches up to the stratosphere and down to the Earth's core ("Because if we fail to do so, somebody's bound to get by it!"). OK, that's hyperbole, but see if the House doesn't at least propose something equally as laughable.

The real battle will take place either in the conference committee or behind the doors of Speaker John Boehner's office. If the House passes their own bill and picks hardliners to sit on the committee, then the temptation will grow for Republicans to just theatrically throw up their hands and declare the effort dead "because Democrats are demanding too much." Lots and lots of major bills get through the House and Senate and die in joint committees, after all. Alternatively (and much more optimistically), Republican senators may sit Boehner down and make their own demand -- that the Senate bill get an up-or-down vote in the House. If a large number of Republicans vote for the bill in the Senate, this is going to put public pressure on Boehner. Privately, the realist Republicans (the ones who know how much their party desperately needs this bill to succeed) may also be putting the screws to Boehner in closed-door meetings. A few of the Republican Party's brightest prospects for 2016 are already on board with the bill, after all. They may ask Boehner a very crass political question of their own: "Do you really want to guarantee Hillary Clinton the White House until at least 2021?" If the Senate bill comes up in the House, there may be enough Republicans (added to an overwhelming portion of the Democrats) to pass the Senate bill intact. The question is whether John Boehner will allow that to happen or not.

But before we get to that point, the next hurdle comprehensive immigration faces is the Senate floor debate. So far, the bipartisan coalition (apparently they've stopped calling themselves a "gang" and are now a "group of eight" instead) has held impressively firm, through over 200 amendments in committee. The bill which emerged from committee is different than the one initially proposed, but not in any deal-killing way, yet. If the core bipartisan group holds together, they may be able to fend off deal-killers on the Senate floor, as well. So the next hurdle may be the easiest one. It may have the most impressive result, as well, if the bill passes with what can only be called "overwhelming bipartisan support."

But after the bill leaves the Senate is when the real fight is going to begin. The language is going to intensify, and temperatures are going to rise. The hurdles are going to get a lot higher, and a lot harder to clear. Whether they can be cleared or not may depend on the final tally the bill gets in the Senate floor vote.

-- Chris Weigant

Cross-posted at The Huffington Post

Follow Chris on Twitter: @ChrisWeigant