The Republican Party has a demographic dilemma. Its largest dependable constituency comprises older white people, a group who vote reliably but who are unlikely to be around in large numbers two decades from now.

You’d think that would prompt Republicans to start courting younger voting blocs with enthusiasm. But one of the fastest-growing blocs — a group gaining electoral influence — happens to be Latinos, a demographic toward whom those older whites have shown significant hostility. Thus, the dilemma.

Republicans’ response to this conundrum has been to take the low road: pandering to the prejudices of its white voters while trying to block ballot access for groups they have alienated with that approach, including Latinos. That’s why, over the last several years, GOP-dominated state legislatures around the country have passed harsh voter ID laws that disproportionately affect voters who tend to support Democrats.

Belatedly, though, the Justice Department is coming to the rescue, attempting to protect the rights of Americans who would likely be harmed by voter suppression tactics. The Civil Rights Division announced last week that it would block implementation of an onerous voter ID law put in place by the GOP-dominated Texas Legislature last year. In December, the Justice Department announced that it would block a similar law in South Carolina.

Thomas Perez, head of the Civil Rights Division, noted that the Texas law would disproportionately affect Latino voters, who are less likely to have a driver’s license or similar state-issued ID than white voters. (The battle isn’t over, since Texas is already seeking approval for the law in federal court.)

Supporters of these ballot-blocking initiatives insist that they are necessary to protect the franchise from fraud, but that’s nonsense. In-person voter fraud is virtually non-existent. The problem in this country is not that corpses or foreigners are showing up at the polls to cast a ballot. The problem, instead, is that too few still-breathing Americans bother to vote.

The real intent of voter ID laws is to shave off a few thousand or a few hundred thousand votes from groups that have tended to back Democrats, including voters of color and, increasingly, young adults. The Texas voter ID law doesn’t even allow college and university identification cards to be used at the polls. If younger voters had not thrown substantial support to Obama in 2008, it’s likely those IDs would have been allowed.

If the Republican Party had an establishment with backbone and moral fiber, it would have pushed back against the prejudices of its ultraconservative base, educating them about the many contributions that Latinos — those who crossed the border with papers as well as those who sneaked in — make to this country. For one thing, they have lowered the age of the average American worker, helping the U.S. stave off the population collapse that is facing countries such as Japan. Younger workers are needed to pay the taxes that fund Social Security for retirees.

Instead, Republicans have engaged in a campaign of condemnation, condescension and hateful rhetoric. Even the DREAM Act, a modest measure that would have offered a path to legalization to about a million young illegal immigrants, provided they serve in the military or attend college, didn’t draw enough GOP support to pass Congress. The GOP presidential candidates have also insisted on policies that would either drive illegal immigrants out of the country or leave them in the shadows, ripe for exploitation.

It’s no wonder that Republican strategists are now terrified that the party has irreparably damaged its relationship with Latinos. Former President George W. Bush had a moderate stance on immigration and earned about 40 percent of the Latino vote in 2004; John McCain, who kept a similarly moderate stance through much of his political career, garnered 31 percent of that vote. But a recent poll by Fox News Latino showed President Obama likely to pick up 70 percent of those voters.

That’s why the Republican Party is trying desperately to keep Latinos from the ballot box.

(Cynthia Tucker, winner of the 2007 Pulitzer Prize for commentary, is a visiting professor at the University of Georgia. She can be reached at cynthia@cynthiatucker.com.)