It is stated as an undeniable fact that the GOP must loosen up on immigration (not that it's very strict, anyway) in order to improve its standing with the Latino Vote.

A recent backgrounder by George Hawley of the Center for Immigration Studies questions that claim. It's entitled Pro-Immigration Congressional Republicans Do Not Perform Better Among Latino Voters, (February 2013) and bases its research on the year 2006.

Why 2006? Well, Hawley writes that

2006 was chosen as the best year to consider the relationship between congressional behavior on immigration and Latino vote choice. This was a year in which immigration was a particularly salient issue...Given the degree to which immigration was a high-profile issue in 2006, this year represents the most recent election year in which there was the greatest chance of uncovering a relationship between congressional behavior on immigration and vote choice in the electorate.

Findings of the research include:

Latinos living in congressional districts with pro-immigration Republican incumbents were no more likely to support the incumbent than Latinos living in districts with Republican incumbents with more restrictive immigration records.

Adopting pro-immigration policies is unlikely to increase the Republican share of the Latino vote based on these results.

There is some evidence that pro-immigration Republican incumbents did worse among non-Hispanic whites, indicating that supporting amnesties is likely to cost Republicans votes among non-Hispanic white voters.

These findings are consistent with what occurred after the 1986 IRCA amnesty for illegal immigrants, signed by President Reagan. The Republican Party lost Latino support from the 1984 to the 1988 presidential election.

In the conclusion, the research is summarized with this explanation:

While the argument that Republican incumbents can boost their share of the vote among Latinos by embracing liberal immigration policies seems plausible, it is not backed up by any empirical evidence. The analysis presented here found no relationship between Republican immigration records and the vote choice of Latinos living in Republican districts. Whether a Republican member of Congress was a strong liberal or a strong conservative on immigration, most Latinos living in Republican districts did not vote for the incumbent in 2006. Thus, Republicans who take a more liberal stance on immigration should not expect to see a corresponding increase in their share of the Latino vote.

Although there was no evidence that Latinos were sensitive to incumbent immigration records when determining vote choice in 2006, there was modest evidence that non-Hispanic whites were more likely to vote for incumbents whose immigration records were congruent with their own attitudes. Because strong majorities of white voters have negative feelings toward illegal immigrants and oppose amnesty, pursuing expansionist immigration policies will likely cost Republican incumbents more votes than they gain.

Isn't this what VDARE.COM writers have been saying all along?