President Obama has indulged in hyper-partisan rhetoric, let on that he’s in favor of gay marriage and pulled the plug on our troop presence in Afghanistan. His base is pleased these days. They should be. His mask of moderation is gone. He’s out there waving the bloody shirt in the class and gender wars.

Meanwhile, CNN reports:

The Public Religion Research Institute poll showed Obama carrying Catholic and mainline Protestant voters, as well as voters who did not identify a particular denomination.

Romney’s lead among white evangelicals was nearly 50 percentage points, as 68 % chose him and 19 % chose Obama in the survey. . . .

Obama’s advantage among Catholic and Protestant voters was less pronounced than Romney’s lead among evangelical voters. Obama carried Catholics 46% to 39% and mainline Protestants 50% to 37%, the survey said.

It showed him having a larger advantage among those who did not identify with a denomination, by a 57% to 22% margin.

Ironically, as each candidate’s base comes home, the swing voters in the center become all the more critical. Both sides, it’s fair to say, have solidified support among key constituents. The rub may be that Obama’s less-regular, younger voters may not show up in droves as they did in 2008. That said, once each side has its maximum support from its respective party you are left with 6 to 10 percent of voters in the middle. (Some of that base-building by the way is wasted effort. Obama has already won deep blue states like New York and California; no matter what he says on gay marriage, those states electoral votes don’t increase.)

Romney in this process has one advantage: Obama had to move left on policies and turn up the left-friendly rhetoric to get back his base, thereby potentially turning off critical moderate voters in swing states. Romney essentially (and ironically) has been able to keep his tone and positions consistent. He remains the “can fix it” businessman who is conservative in temperament but not ideologically driven. In other words, Romney hasn’t sacrificed his appeal to moderates while getting back his base, in large part because between Hilary Rosen and Obama’s “evolution” on gay marriage, his base came to him.

When you see a Web ad or hear an interview with one of the candidates, you should imagine how, for example, an under-employed worker in Ohio, a mother in Florida, a financial adviser in the Philly suburbs or a Hispanic small businessman in New Mexico would react. Those may be the voters in the sorts of places who haven’t already lined up with a candidate. They are influenced not only by the economy, but also by intangibles (Is this guy responsible? Could I stand hearing that one for four years?)

Given that those are the people in play, Romney has the advantage for now in focusing on the issues those particular voters care about. He also has an effective argument that on the issue they care most about, the economy, the president isn’t up to the job. Obama’s problem with these voters — who are indifferent to or slightly hostile to the idea of gay marriage, don’t much like a lot of name-calling and have been hobbled by the anemic recovery — remains: What is he going to say to them?

At some point, if Romney clears the bar that Republican challengers usually face (He’s not a nut, right?) Obama may find it difficult to devise an effective appeal to the most critical voters of all. If you think about it, just about everything Obama has done over the last year has been designed to corral the left. Now, what’s he going to do to win the voters who matter most?