Over the weekend, as the Conservative Political Action Conference wound down, Michele Bachmann was greeted with a roar of approval when she said this:

“The last thing conservatives should do is help the president pass his number-one goal, and that’s amnesty.”

CPAC showcased that deep divisions remain among Republicans over whether to pursue immigration reform. The conservative interpretation of the GOP dilemma appears to be that passing reform is a no-no because it would be a gift to the hated Obama (whom you can’t trust in any case). Never mind whether it’s the right thing to do politically for Republicans, not to mention the right thing to do on policy.

And so reform may have to wait until Obama leaves office. Which would mean Republicans will head into the 2016 election without having repaired their Latino problem.

A new analysis performed at my request by political scientist Michael McDonald, who heads the United States Elections Project and studies voting patterns, underscores once again the perils this holds for the GOP.

The analysis finds that the share of the eligible voting population that is Latino will rise by two percentage points from 2012-2016 in three critical presidential swing states: Florida, Colorado, and Nevada. It will rise by two percentage points in New Mexico, Texas, and Arizona. And it will rise by one percentage point in Virginia, Georgia, and North Carolina. While that last finding may seem negligible, it is a sign demographics in those three states — one purple swing state that’s key in presidential elections; the others long reliably red — are trending in a favorable direction for Dems:

McDonald’s analysis, which is based on current and projected American Community Survey data, was put in chart form by the crack Post polling team. Drag your cursor over the bars to see percentages.

GOP pollster Whit Ayres, who favors reform, tells me Republicans should take the two point rise in critical swing states very seriously.

“It’s significant,” Ayres says. “Some aspects of the future are difficult to see clearly. The increasing proportion of Hispanics in the electorates in key swing states is not one of them.”

“Swing states are by their very definition closely contested,” Ayres continues. “Many of them have been won in close races by only a percentage point or two. Changing the demographics of the state by two percentage points puts a finger on the scale in each of the swing states for the party that’s doing well among Hispanics. This underscores the critical importance for Republican candidates to do better among nonwhite Americans, particularly among Hispanics, if Republicans ever hope to elect another president.”

Ayres adds that the one-point rises also matter. “It is a sign of things to come,” he said. “States that have been comfortably red, like Georgia and North Carolina, are changing, and will become swing states unless Republicans figure out how to win significant support in the Hispanic community.”

Jennifer Duffy, who analyses Senate races for the non-partisan Cook Political Report, says such changes could even impact 2016 Senate contests. Even if Republicans win a slim Senate majority this year, Cook projects that in 2016, Republicans will be on defense in many more races, amid a more diverse presidential year electorate. There will be contested races in Florida (Marco Rubio); North Carolina (Richard Burr), and possibly Arizona (especially if John McCain retires).

“In 2016, Republicans have to defend pretty hostile territory, and the fact that it’s a presidential year will only make it worse,” Duffy tells me. “All of that could be made much more serious if Republicans don’t address immigration in some way. In a lot of these states, if Republicans win on the strength of the white vote, they may not be able to count on that again in 2016. This is true for even someone like Marco Rubio. The longer Republicans stall on immigration, the harder it is going to be for them.”

All of this underscores what Ron Brownstein has argued: The makeup of the 2014 Senate map — where control will be decided in states that are older, whiter, and redder than the diversifying national electorate — is such that Republicans could temporarily recapture the Senate this fall without doing a thing to broaden the party’s appeal to “diverse America” and the portions of the white electorate that are comfortable with diverse America. But even if that happens, the barriers blocking Republicans from appealing to those groups will remain as 2016 looms.

Here a caveat is in order. Just because the percentage of Latinos in the eligible voting population will increase, it doesn’t mean Latino votes will rise accordingly, since many may not turn out. Sean Trende has argued that Republicans may be able to offset demographic problems by increasing their share of the white vote, and has noted that Dems can’t count on the same levels of non-white turnout that Obama enjoyed.

But even if that is true, the broader point is that the long term fundamentals underlying all of those variables are shifting in ways that will likely continue helping the party with broader appeal to Latinos — and likely continue hurting the one that alienates them.

“These are significant changes,” McDonald says. “This is the canary in the coal mind. The trend is there. We know it’s going to happen. There’s no reason to assume these trends won’t persist. The future is now.”

Greg Sargent writes The Plum Line blog, a reported opinion blog with a liberal slant -- what you might call “opinionated reporting” from the left.