The Wisconsin primary is taking place on Tuesday, and 42 delegates are at stake in the contest.
The latest polls show Mitt Romney leading rival contenders Rick Santorum, Newt Gingrich and Ron Paul by a comfortable margin going into the vote. The former Massachusetts governor is already looking beyond the primary race and trading attacks with President Barack Obama.
Maryland and Washington, D.C. are also holding primaries on Tuesday. Romney goes into the contests with 572 delegates. Santorum currently has 272 delegates, while Gingrich has 135 and Paul has 51.
Click here for a rundown on who's ahead in the race for the Republican presidential nomination.
Below, a live blog of the latest developments to unfold on primary day.