One of the most reprehensible developments in the presidential campaign is the Republican effort to make it difficult for Latinos to vote by challenging their citizenship in states where such tactics could give Mitt Romney victory in the November election.

This tactic comes on top of long-standing Republican efforts to eliminate the votes of African-Åmericans who, like Latinos, overwhelmingly support President Barack Obama. What makes the campaign against Latinos different is that it questions the citizenship of this growing group of Americans, disparaging their right to live in this country legally and be part of its political process.

It’s just as bad as an Arizona cop stopping Latinos and demanding proof of citizenship. The message is clear: If you are Latino and want to drive or vote, you’d better have your papers in your purse or pocket.

The stakes are high. There could be more than 25 million Latinos eligible to vote this year. Unfortunately, their voting participation has been low — 31percent in 2010 compared to 49 percent for non-Hispanic whites and 44 percent for African-Americans.

The latest effort at mass disenfranchisement exploded after Republican governors and state legislators, elected in 2010, passed a number of laws clearly aimed at suppressing the Latino vote. The enactment of these laws, while covered in local newspapers, has generally slipped the attention of the national political news media.

This week a report by a civil rights organization, the Advancement Project, focused attention on the issue again.

“The Latino community is a large and integral part of American democracy, comprising more than 10 percent of the nation’s eligible voters and approximately 8 percent of its registered voters,” said the report, “Segregating American Citizenship: Latino Voter Disenfranchisement in 2012.” In some states, the total is considerably higher.

“This report finds that 23 states currently have legal barriers that disproportionately impact voter registration and participation by Latino citizens. These obstacles could deter or prevent more than 10 million Latino citizens from registering and voting in the 2012 elections.”

In many states, the number of eligible Latino citizens that could be affected by these barriers exceeds the margin of victory of the 2008 presidential election. In Florida, for example, eligible Latino voters amount to nine times the 2008 Obama margin of victory, and in Colorado, the number of eligible Latino voters is twice his victory margin in 2008.

A prime method of stifling the Latino vote, the report said, is through purges of voter rolls, a customary procedure usually designed to remove from the voter lists the dead or those who have moved and not changed their registration. Now, it is often directed at Latinos.

This year, several states began comparing their voter registration rolls with often-faulty federal immigration records. “The trend accelerated in July 2012, when the total number of states seeking to compare their voter registration rolls with immigration databases increased to 16. The method disproportionately targets naturalized Latino citizens who may improperly be identified as noncitizens under these programs,” the report said.

Other methods that discourage Latino voting are demands for citizenship papers before registering and for photo identification at the polling place, which also affects elderly voters, the poor and African-Americans.

Another method to stifle the pro-Obama vote is to reduce the number of days for advanced voting, important in poorer African-American communities where it is a tradition for people, often without cars, to board buses together after church and go to the polls. Ohio and Florida are among the states trying to eliminate that custom.

“In my lifetime, nobody has ever done anything quite so blatant,” former President Bill Clinton told Fareed Zakaria on CNN Sunday. Elizabeth Drew, writing in the New York Review of Books this week, put it this way: “The Republicans’ plan is that if they can’t buy the 2012 election they will steal it.”

The legal landscape in the area is ever changing as state and federal courts rule on the new laws, sometimes in conflicting ways. Many of the laws will remain on the books on Election Day and even when laws are stricken, the false impression they create that voting is difficult or impossible for some can be enough to suppress voter turnout.

In addition, organizations such as True The Vote, a tea party group, is planning to have “observers” in key states to check the voter rolls against records they have assembled, often inaccurately. They also plan to go into polling places in minority communities, hanging around, taking notes and generally trying to act in an intimidating manner.

True The Vote and other groups say they are trying to prevent voter fraud — an offense that the overwhelming majority of research shows scarcely exists.

In his book “The Voting Wars,” professor Richard Hasen of UC Irvine calls groups trying to find fake voters “the fraudulent fraud squad.” He analyzes the strong Republican connection to such groups and points out that in the view of Republicans, when Democrats win, elections “are stolen from Republicans. When Republicans win, the cry fades away. Voter fraud? What voter fraud?”

The News 21 project, part of the Carnegie-Knight Initiative on the Future of Journalism, analyzed 2,068 alleged election-fraud cases since 2000 and found that while fraud has occurred, the rate is infinitesimal. And fake voters, trying to use someone else’s name, are “virtually nonexistent.”

All these Republican voter suppression schemes are bad. But none of them is so contemptuous of democracy as the effort to question the citizenship of Americans, particularly naturalized citizens, who want to exercise their right to vote.