Voters are currently going to the polls to vote in the Republican primaries in Wisconsin, Maryland and the District of Columbia.  So far it looks like it should be a very good night for Mitt Romney. DC and Maryland polls close at 8 pm Eastern; Wisconsin polls close at 9 pm Eastern.

In Maryland Romney is expected to do so well most pollsters haven’t even bothered to survey the state. The only recent poll of the state from PPP has Romney with a huge 25 point lead. It found Romney at 52%, Rick Santorum at 27%, Newt Gingrich 10% and Ron Paul at 9%. If Romney wins by this margin he will likely net nearly all the delegates up for grabs.

In the District of Columbia no one has bothered to poll the nation’s capital, in large part because Rick Santorum didn’t even qualify for the ballot. Romney should easily win DC and its 16 delegates.

Wisconsin is the only contest today where that is at least some suspense about the outcome. The demographics of the state don’t particularly favor either Romney or Santorum, but all the latest polling consistently has Romney with a modest lead. The Real Clear Politics polling average has Romney 40.3%, Santorum 32.8%, Paul 10.7% and Gingrich 7.8%.

For Santorum Wisconsin is pretty close to a must win, even though victory tonight seems unlikely. He may keep running if he loses today, but almost no one will think he has a serious chance of winning the nomination. The sense that Romney is inevitable is growing almost daily. The only way for Santorum to stop it is with a narrative changing victory over Romney. If Santorum doesn’t win Wisconsin this evening, it will be another three weeks until the next set of primaries on April 24th, and Romney is favored to win most of those states.