Mitt Romney has erased Rick Santorum's lead in Wisconsin a week before the state's Republican presidential primary, surging to a comfortable margin, according to a new poll from Marquette Law School.
The poll shows Romney with 39 percent and Santorum at 31 percent. Ron Paul was at 11 percent in the state, and Newt Gingrich at 5 percent.
In late February, the previous poll by the school found Santorum with a huge advantage in the state: 34 percent to Romney's 18 percent.
Romney's boost has likely been helped by a huge influx of cash from his campaign and his super PAC Restore Our Future. Romney and his allies have spent a combined total of $3.02 million on advertising in the state, according to a source tracking GOP media buys.
Santorum and his Super PAC Red White and Blue Fund have spent considerably less - $358,625, according to the same media tracking source.
There are 42 delegates at stake in Wisconsin's primary, and they will be awarded on a winner-take-all scheme, raising the stakes for all the candidates.