• District of Columbia primary results
• Maryland primary results
• Wisconsin primary results
• Santorum WI vote boosted by Democratic crossovers
Republican presidential candidate Mitt Romney swept three primaries Tuesday, crossing the halfway mark in the delegate race and intensifying the air of inevitability that he will be the GOP's nominee.
Romney prevailed in Maryland, the District and Wisconsin and walked away with at least 70 new delegates. The former Massachusetts governor ended the night with a total of more than 630 delegates, more than half of the 1,144 needed to secure the nomination.
"Winning these three states is going to drain the life out of the Republican opposition," pollster Ron Faucheux, president of Clarus Research Group, told The Washington Examiner.
Romney didn't even mention opponents Rick Santorum, Newt Gingrich or Ron Paul when he addressed supporters in a Milwaukee victory speech. Instead, he implored the crowd to help him win the next round of primaries in late April and take on President Obama in the fall.
"Tonight, I'm asking the good people of Connecticut, Delaware, New York, Pennsylvania, and Rhode Island to join me," Romney said. "Join me in the next step toward that destination of November 6, when across America we can give a sigh of relief and know that the promise of America has been kept. The dreamers can dream a little bigger, the help wanted signs can be dusted off, and we can start again."
Romney has a huge lead in the delegate race over all three of his opponents, but none of them have any plans to drop out.
Romney's chief opponent, Santorum, made a bee line to his home state of Pennsylvania, where he hopes to reinvigorate his campaign with a primary victory there on April 24.
Santorum told a crowd near Pittsburgh he plans to remain in the race and has set his sights not only on the Keystone State but has "every intention" of winning in Texas primary in May.
"We have now reached the point where it's halftime," Santorum said. "Whose ready to charge out of the locker room in Pennsylvania for a strong second half?"
But Santorum's chances of winning are fading fast. After Tuesday, the delegate equation would require Santorum, with fewer than 300 delegates, to win more than 70 percent of the remaining delegates to secure the nomination. With a slate of moderate-dominated Eastern states on the primary lineup, the conservative contender is not likely to achieve anything close to that total.
Gingrich and Paul on Tuesday faded further into campaign obscurity, with neither registering much support in any of the contests, though Paul cracked double digits in Wisconsin.
Gingrich, who has already pared back his cash-strapped campaign, pledged to remain in the race until Romney gets the nomination, though his campaign schedule appears modest.
While Santorum and Romney head next to Pennsylvania to battle for that state's 72 delegates, Gingrich is headed to Delaware, with just 17 delegates, and North Carolina, which does not hold its primary until May 8.
Wisconsin exit polls show voters are less enthusiastic about finding a more-conservative alternative to Romney, with 80 percent convinced Romney will be the nominee.
"I think after tonight you are going to see a new level of the sense that this is over," Faucheux said. "And the voters in Wisconsin have come to that conclusion."