Republicans opposed to comprehensive immigration reform often cite the rule of law as their main reason for reticence.

Some claim legalizing up to 11 million undocumented immigrants would hurt the economy, or American workers. But many Republicans are blunt: they don't want 11 million new Democrats voting in American elections.

That's the conventional wisdom, that undocumented immigrants will inevitably vote Democrat once they become citizens. It's not a ridiculous claim, but the real outcome is far more uncertain.

In last year's presidential election, 71 percent of American Hispanics voted for the Democrat, Barack Obama. Only 27 percent voted for Mitt Romney. Traditionally, Republicans grab about 30 percent of the Hispanic vote; the last time they performed so poorly with the Latino demographic was 1996, when Bob Dole only got 21 percent.

But undocumented immigrants are less tied to any political party. While they still favor Democrats, fully 65 percent have no political leanings. Of course, this could change if they gain the right to vote. Why pay attention the political process if you can't do anything to influence it?

Still, concerns over the political affiliations of undocumented immigrants are overblown. Under the Senate's immigration reform plan, the first applicants won't be eligible for citizenship (and therefore eligible to vote) for 13 years. 2026 is a long way off, and plenty of demographic shifts will have a much greater impact than immigration reform before then.

The first presidential election affected by this influx of new voters won't be until 2028. Before then, the impact will be spread across the country in local elections, where any notion of a "bloc" of liberal Hispanic voters runs up against the reality of the federal system.

However, it is difficult to escape the fact that the majority of Hispanics, undocumented, legal or native-born, prefer the policies of the Democratic Party. Republicans would reap greater benefit from a policy shift rather than barring entry.