Romney's rivals have tried to block his seemingly unstoppable road to victory, pledging to stay in the race until the party's convention in August, in Tampa, Fla. By the rules of the Republican Party, the nominee must win 1,144 delegates, who are divvied up after each state primary; Romney is the only candidate who has a realistic path to get to that number, an argument that his campaign has made repeatedly.
Tonight's three victories extend Romney's lead even more. Most of Maryland's 37 delegates and Wisconsin's 39 are likely to go to Romney, and he'll get all of Washington's 16, too. Santorum didn't even qualify to be on the ballot in the District.
A figure that will stick out no matter how well Romney performs is the money that has been spent in his favor -- a dollar amount that Democrats are sure to say indicates that his appeal is artificial. For example, the Romney campaign and the super PAC supporting it have spent more than $3 million on TV ads in Wisconsin, four times as much as Santorum and his super PAC have spent.