Democratic presidential hopefuls (both announced and not-yet-announced) are already beginning to define their candidacies in their speeches. The field is going to be so large this time around that they'll all be searching for ways to stand out from the pack. Many basic Democratic agenda items will be very similar from candidate to candidate, making nuanced differences all that separates them. Two of these candidates -- one announced, one not -- took the occasion of Martin Luther King Junior Day yesterday to explicitly call for a constitutional amendment guaranteeing the right to vote. This is a much more potent political issue than most folks who reside inside the Beltway realize, and it may just become a dealbreaker issue for the presidential field.

Many are unaware that the U.S. Constitution does not explicitly guarantee the right to vote. While a full seven out of the 17 amendments ratified since the Bill of Rights do deal with voting rights in one way or another (such as granting the franchise to women and to 18-year-olds), there is no actual phrase or amendment within the Constitution that simply says that every citizen has the right to vote.

At first glance, this may sound like a rather academic issue. After all, the right to vote plainly exists (see all those people turning out at every election...), but the important part is that federal law does not guarantee the right. Which means that the states -- which oversee the entire elections process -- can be radically different in defining such rights. Ex-felons can vote in one state, but not another. One state has no I.D. requirement, one state allows for college I.D.s to be sufficient, but another state demands drivers' licenses. There are dozens (if not hundreds) of such distinctions from state to state -- meaning that your right to vote depends entirely on which state you actually live in. It is not currently a federal right defined in the Constitution, in other words. States can get away with extremely strict regulations, unless Congress or the federal courts stop them.

The right to vote has been under assault from the Republican Party for decades now, but in the past ten years or so they've ramped up their efforts to deny the vote to as many groups of people (who might just vote Democratic) as possible -- to levels not seen since the days of poll taxes and literacy tests in the Deep South. All of the laws and practices passed have been specifically designed to make it harder for certain groups of people to vote. These groups, unsurprisingly, have been core Democratic Party supporters. This is unfair, and it's about time Democrats fought back using the biggest weapon in the constitutional arsenal -- amending the Constitution itself. All of these minor skirmishes would be a lot easier to fight in the courts if a constitutional right to vote existed.

Which is why I applaud the news that both Elizabeth Warren and Bernie Sanders explicitly called for a "Right To Vote Amendment" in their speeches yesterday. I'm hopeful that other Democratic presidential candidates will also get behind this idea, if they haven't already done so (to be fair, since I have not checked each of their campaign websites to see). I'd love to see this as a plank in the national party's platform, as well. Sure, an amendment is a long process with no guarantee of success, but that shouldn't stop any Democrat from promoting the idea. You've got to start somewhere, and a presidential campaign seems like a dandy place to do so.

The idea of a Right To Vote constitutional amendment is not a new one, but it has become a lot more urgent with all the voter suppression efforts in play right now. FairVote.com has been pushing for such an amendment for a while now. Their proposal is about as straightforward as you can get. Here is the full text of their proposed amendment:

SECTION 1. Every citizen of the United States, who is of legal voting age, shall have the fundamental right to vote in any public election held in the jurisdiction in which the citizen resides.

SECTION 2. Congress shall have the power to enforce and implement this article by appropriate legislation.

Short, sweet, to the point. Every citizen -- no matter where he or she resides -- shall have the same fundamental right to vote. Congress will determine election rules for the whole nation, period. The states must adhere to national standards, because voting is a fundamental American right.

The issue is a good one for Democrats right now for multiple reasons. The first is that the right to vote is already under attack, and Democrats have been losing a lot of these battles in the statehouses. This gives the effort a fierce urgency it might not have had ten or twenty years ago. The second reason it is a good political issue for Democrats is that, at heart, it is a matter of fairness. And every American understands fairness. It's hard to be against fairness, in other words. Opposing such an amendment is going to be pretty near indefensible for Republicans to do. How can any sane individual argue against guaranteeing the right to vote, after all?

The argument will be made that it is a very high bar to clear, since three-fourths of the state legislatures have to ratify it, and that's after getting it through Congress (which will be no picnic either). But that shouldn't stop any Democrat from making the attempt. Because the more Republicans fight back against the idea, the more public their opposition becomes, and the easier it is for Democratic politicians to use it as a blunt object against them on the campaign trail. If one party is standing for a constitutional right to vote and the other party isn't, well, that's a pretty clear sign of who is on the side of fairness, right? The election ads would just write themselves, and not only at the national level. If Democrats actually did get such an amendment out of Congress and it did go to the states, then it would be a great issue for Democratic politicians to get elected on at the state level all across the country -- even in red states. So politically, even if it takes a long time, it is still a great issue for the Democratic Party in the meantime.

Republicans have been much more successful in pushing constitutional amendments and using the issue out on the campaign trail to stymie Democrats. Remember the big push for an anti-flag-burning amendment? Or how about for a "defense of marriage" anti-gay amendment? Neither one got very far along the path an amendment has to travel, but the Republicans sure made a lot of political hay over them in the meantime. Why shouldn't Democrats do the same thing, especially on an amendment that any American should be proud to see ratified rather than one designed to divide us?

The timing is right, because of all the success Republicans have had in their voter-suppression efforts. Proposing an amendment is the very definition of dreaming big, politically. It's a bold move, but in the case of the right to vote, it's easy to argue how necessary such a thing has become. Why should Americans face 50 different sets of voting rules, depending on which state they live in? Why shouldn't the right to vote be a federal issue? This is precisely the type of boldness that I, for one, will be looking for in a presidential candidate. The time for incrementalism is over. Seeing America's voting rights nibbled away, one state law at a time, should be fought back against in the strongest way possible. Which is why I applaud both Bernie Sanders and Elizabeth Warren for explicitly calling for a Right To Vote Amendment, and I hope all the other candidates will also start supporting the effort as well.

-- Chris Weigant

Follow Chris on Twitter: @ChrisWeigant