Mitt Romney has taken a big step in his quest to become the Republican Party's nominee to face President Barack Obama this November in the presidential election.
Romney won all three primaries on April 3 in Wisconsin, Maryland, and Washington D.C.
The losses were a huge setback for his nearest rival Rick Santorum who is now badly trailing Romney in both delegates and fund raising.
In his victory speech in Milwaukee, Romney ignored Santorum, instead sharply criticizing Obama for his handling of the U.S. economy and high gasoline prices.
"Out-of-touch liberals like Barack Obama say they want a strong economy, but in everything that they do they show they don't like businesses very much," Romney said.
"But the economy of course is simply the product of all the businesses in the nation added together. So it's a bit like saying you like an omelettes but don't like eggs."
In a sign that Obama sees Romney as his chief obstacle to reelection, the president singled him out by name and criticized him in a speech on April 3.
Based on reporting by Reuters and AP