When George W. Bush’s narrowly won reelection in 2004, not a single American state had a law requiring voters to present photographic identification at the polls. Today about 10 states, with 134 electoral votes among them, have enacted such laws—all at the prompting of Republicans.

Republicans are not responding to a newly discovered crisis in voter impersonation at the polls, but to a partisan crisis brought on by their party’s declining base of white Protestant voters. If the GOP can’t grow its own voter base, it can at least hope to shrink the Democrats’ base.

Photo-identification laws are targeted heavily at Democratic minority voters, who are significantly less likely than whites to possess the required identifications. A reduction in the votes of racial minorities relative to the votes of reliably Republican white Protestants benefits the GOP. In an unguarded moment, Pennsylvania’s state House majority leader, Republican Mike Turzai, said that his state’s newly enacted photo-identification law “is gonna allow Governor Romney to win the state of Pennsylvania.” In a response to a lawsuit challenging the law, the state’s attorneys admitted that they were “not aware of any incidents of in-person voter fraud.” Impartial studies have reached similar conclusions about voter impersonation across the nation.

In contrast to voter fraud, the decline of the Republican’s base vote is real and pervasive. America is no longer a white Protestant nation. Until the late-20th century, white Protestants had composed the majority of Americans and the overwhelmingly majority of voters. That white Protestant majority has since disappeared. Fewer than 40 percent of all Americans today are white and Protestant, though the group, which tends to be older and more likely to vote, is usually overrepresented at the polls.

The percentage of white Protestants among voters will continue to slide as America becomes increasingly non-white. The big states of Texas and California are already majority non-white and all of America is likely to follow suit before mid-century according to US Census projections. Hispanics, the nation’s largest minority group, are increasingly gaining citizenship and voting. African American voter turnout now closely approximates that of whites.

The dependence of the Republican Party on white Protestant voters is deeply rooted in the party’s history. The modern Republican Party took shape in the 1920s out of a widespread concern that secular, pluralistic, and cosmopolitan forces threatened America’s national identity as a white Protestant nation. At the core of conservative politics both in the 1920s and today is the ideal of America as a unified nation that upholds traditional white Protestant values.

White Protestant voters overwhelmingly backed Republican candidates in the early 20th century, with the exception of the South, which was solidly opposed to the party of Lincoln until later in the 20th century. Racial and religious divisions in voting remain pervasive today, far overshadowing divisions of gender or class. And white Protestants are still overwhelmingly Republican. In 2004, according to exit polls, George W. Bush won two thirds of the white Protestant vote, but only about 11 percent of the African-American vote, 44 percent of the Hispanic vote, and 25 percent of the Jewish vote. In 2008, John McCain won 65 percent of the white Protestant vote, but only about 5 percent of the African-American vote, 31 percent of the Hispanic vote, and 21 percent of the Jewish vote. Republican support among evangelical, white Protestants has been especially impressive, with Bush winning 79 percent and McCain 73 percent.