His biggest test will probably be Wisconsin on April 3. Polls show that Romney holds a narrow lead, but former Pennsylvania Sen. Rick Santorum has the potential to win that primary and break Romney's string of victories in diverse Midwestern states such as Illinois, Michigan and Ohio. And that could delay Romney's progress toward the nomination and create more doubts that he can rally his own party behind him.
However, Romney remains in a very strong position. He is expected to win both Maryland and the District of Columbia, which also hold primaries on April 3, and this would add to his delegate haul and keep him firmly in the lead.
After that come the tests on April 24, when Connecticut, Delaware, New York, Pennsylvania and Rhode Island hold primaries. Romney is likely to win the lion's share of delegates on that day.
Romney scored an impressive victory Tuesday in the Illinois primary, but it doesn't appear to be creating any momentum for him in Louisiana. That's because evangelicals, blue-collar Republicans, and very conservative voters are likely to dominate that primary, and such voters have strong doubts about whether Romney is sufficiently conservative. The latest PPP poll has Santorum ahead of Romney in Louisiana, 42 percent to 28 percent, with former House Speaker Newt Gingrich at 18 percent and Texas Rep. Ron Paul at 8. The Rasmussen poll has similar results, with Santorum at 43, Romney at 31, Gingrich at 16 and Paul at 5.
But the former Massachusetts governor is now the clear front-runner, with double the number of nominating delegates, 563, as Santorum, his closest competitor, who has 263, according to the Associated Press. Gingrich has 135 and Paul has 50. Romney's path to the nomination, while still a bit bumpy, seems clear.