Santorum met privately Thursday with conservative activists to work on plans to stop Romney's march to the nomination. The group decided to pressure Gingrich to leave the race, believing that would help unite conservatives behind Santorum.
Gingrich, however, has already scaled back his campaign to the point that he schedules few public events. In the three primaries last Tuesday, all won by Romney, Gingrich got 11 percent of the vote in both Maryland and the District of Columbia and 6 percent in Wisconsin.
Even if Santorum had picked up every vote for Gingrich, Romney still would have won all three primaries.
"It's over with," said Bennett, the RNC member from Ohio. "And if Romney carries Pennsylvania, that completes it. He'll be the presumptive nominee before the end of the month."
Associated Press writers Brian Bakst in St. Paul, Minn.; Kantele Franko in Columbus, Ohio; Peter Jackson in Harrisburg, Pa.; and Will Weissert in Austin, Texas, contributed to this report.
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