Just a few years ago, the idea of “mobilizing the student vote” made veteran politicos laugh into their dinner napkins: The thinking was that young voters never show up in large enough volumes to sway elections, and that young people were simply too callow to live up to their supposed ideals.

But a funny thing happened in 2008: The young (along with minorities) really did show up at the polls, and they helped carry Barack Obama to victory. Now those old politicos have taken note, and are busy trying to enact laws that make it harder and harder for students to vote, as you can see in this infographic by Campus Progress, a youth-centered offshoot of the Center for American Progress, a liberal think-tank:

These changes center on creating laws that make voters present proof-of-residence documents. But college students–who often spend nine months out of the year away from home–often can’t provide such docs, beyond just student I.D.’s. (Granted, students could theoretically re-register as in-state residents, but think about your own college experience. Did you? I’ll bet you kept your home-state driver’s license. Also, remember that student voters tend to register at the last minute — when it’s too late to get formal residency changed.)

The changes aren’t an accident: As The Washington Post reports, they’re part of a coordinated movement led by Republicans, and efforts have been particularly hot in states such as New Hampshire, Wisconsin, and North Carolina, which are all expected to be battleground states in the 2012 elections.

Granted, there is debate about the motives at work: Tea partiers have claimed that these bills are designed to lower costs associated with registering new voters close to election deadlines (all those expensive voter cards, you know), and Republicans have claimed that these laws simply fight voter fraud. (Democrats counter that no evidence of voter fraud exists.)