Santorum mocks Romney at Tucson event

TUCSON, AZ - Rick Santorum acknowledged Wednesday that he's probably running behind Mitt Romney in Arizona, but he implored a tea party crowd not to settle for "a Johnny-come-lately to the conservative cause."

The former Pennsylvania senator told 400 people that Romney proposed a lower corporate tax rate long after Santorum had done so.

"Welcome to the party, governor. It's great to have you along," Santorum said as the crowd hooted and cheered.

WATCH A PORTION OF SANTORUM'S SPEECH IN THE VIDEO PLAYER ABOVE

Polls show Romney, a former Massachusetts governor, running ahead in Arizona, where a strong Mormon presence should help in Tuesday's GOP presidential primary. Arizona has a winner-take-all system for awarding convention delegates, so a close-second finish by Santorum would be a moral victory at best.

Santorum urged the crowd not to accept "a pyrrhic victory," which he says would be the result and come at too great a cost if the party settles for Romney because he is seen as having a better chance at defeating President Barack Obama.

The crowd laughed and clapped when Santorum said America doesn't need a leader who has been "a well-oiled weather vane," a veiled reference to Romney's changed positions on various issues.

Santorum aimed his sharpest barbs at Obama. He said the president's economic plan is "more food stamps and government dependence," comments that echoed rival Newt Gingrich's assertions about Obama's policies.

Santorum also pressed his theme that Obama has ulterior motives for some of his social policies. He said Obama cares about Americans "enough to get them addicted to government programs so he can get their vote."

Some tea party activists who warmed up the crowd labeled local Democratic lawmakers as anti-American. Republican congressional candidate Gabby Saucedo Mercer said Obama "is a communist."

Santorum also spoke about border security and vowed to secure the U.S. borders.