Mitt Romney is poised to pick up more wins in the Republican presidential primary race Tuesday when voters hit the polls in Wisconsin, Maryland and Washington, D.C.
The former Massachusetts governor is widely expected to dominate competitors in Maryland and his closest rival, former Pennsylvania Sen. Rick Santorum, failed to even qualify for the D.C. ballot.
"We know from exit polling in many states that have already voted that Romney and Santorum draw from very different sectors of the Republican Party," says Dave Karol, a government professor at University of Maryland. "Santorum does better with evangelical Christians, rural people, with less educated, less wealthy people. This is not a good state for him."
Recent polling supports Karol's assessment, with Romney holding around a 2-to-1 advantage over Santorum in Maryland.
Santorum, who trails Romney in the all-important race for delegates, refuses to concede and continues to beat Romney in the more conservative and so far largely southern primaries. In fact, Santorum won the last contest held on March 24 in Louisiana. Despite this, the GOP establishment has begun to coalesce around Romney, aiming to put an end to what has become a bruising primary.
And though Santorum initially led Romney polling in Wisconsin, it now appears that Romney will also cruise to victory in the Badger State.
"It's true, five or six weeks ago, Santorum was ahead in Wisconsin, but there's a lot of volatility in these polls and the state polls reflect what's going on nationally, reflect who's up, who's not up," says John McAdams, a political science professor at Marquette University. "Of course, Romney is now ahead in high single digits in pretty much all the polls, so it looks to me that the story is pretty much like the story in the other upper Midwest states."
McAdams notes Santorum had come very close to beating Romney in other Midwestern states, including Michigan and Ohio. As in those other contests, Romney's campaign and groups spending on his behalf have far outspent Santorum.
"There's an absurdly large number of robocalls that are occurring," McAdams says. "Way more than in any previous election, and they are disproportionately for Mitt Romney, because he spends more money than Santorum."
Santorum will be buoyed by evangelical Christian voters, McAdams says, and perhaps some mischief-making Wisconsin Democrats turning out for local elections, because Wisconsin has an "open" primary.
Santorum leads Romney among independent of Democratic voters 37 percent to 32 percent, according to a recent survey by Public Policy Polling.
"If those non-Republicans don't actually end up turning out, Romney can expect to win by a wider margin," writes Tom Jensen, PPP's polling director.
Overall, Romney leads Santorum in Wisconsin 43 percent to 36 percent, according to the survey.
McAdams says it will be important to watch returns for Santorum in the more rural parts of Wisconsin, where support for Santorum as has typically been strong. Romney will need— and is expected to receive—strong support in suburban counties.
"For the most part, the rural areas are pretty conservative and Santorum might be expected to do best," he says. "Ex-urbs are outside the city and considered pretty mainstream Republican, and Romney should do pretty well in those and the more liberal suburbs."