Here’s some political hardball on the immigration front: The Center for Immigration Studies says in a new report that unless Republicans can limit the flow of immigrants from Latin America — as the center wants to do — then the GOP will be doomed to political irrelevance, and soon.

University of Maryland political scientist James G. Gimpel studied election returns and census data and wrote in the report that Latino immigrants are gravitating to the Democratic Party, particularly in urban areas, which spells trouble for Republicans. President Obama and other Democrats did particularly well among Latino voters in 2008 — even in Florida, where for decades Republicans have had strong support in the Cuban-American population.

The GOP’s best bet to avoid electoral disaster, Gimpel argues, is to make a case for limiting the flow of low-skilled immigrants while allowing entry to those more likely to become Republicans because of their greater skills and earning potential.

Gimpel says in the report that Republicans should disabuse themselves of the notion that they will ever win over new immigrants. Because most immigrants settle in big cities dominated by the Democratic Party, he says, they are quickly socialized into it, even in cases where the local Republican Party has adopted immigrant-friendly policies.

To think that immigrants can be won over by currying favor with them “sort of presumes that party attachments are whimsical,” Gimpel says. In reality, “party attachments are very stable and enduring. People tend to settle on a party and stick with it.”

In examining county-level voting data in presidential elections between 1980 and 2008, he found that in urban counties with high levels of immigration, there was a decided shift toward the Democrats. And the more immigrants there were, the worse for the GOP: Among counties of at least 50,000 people, where the immigrant population increased by at least 2 percentage points from 1980 to 2008, 62 percent saw a decline in the Republican share of the vote.

In counties with at least a 4 percentage point increase in the immigrant population, 74 percent saw a decline in the GOP vote. And in counties with at least a 6 percentage point gain in the immigrant share, 83 percent saw a decline in the GOP share.