Presidential candidate Rick Santorum implored conservatives Friday not to settle for Mitt Romney's more moderate record, and to instead insist on nominating an unapologetic conservative that "the party's excited about."

Speaking to a packed crowd at the annual Conservative Political Action Conference, the former senator tried to capitalize on his surprising victories over Romney in the Colorado and Minnesota caucuses this week. He dismissed the idea of reaching out to moderates, saying conservatives' whole-hearted enthusiasm is needed this year.

Santorum said Romney's record on health care and global warming would make it impossible for him to draw the needed contrasts with President Barack Obama this fall.

Santorum never mentioned Romney by name, but he left no doubt of his intent by criticizing his rival's record as Massachusetts governor. Romney's policy of requiring that state's residents to obtain health insurance is "the stepchild of Obamacare," Santorum said.

Obamacare 'will crush economic freedom'

He said the Obama-backed 2010 health care law "will crush economic freedom." He urged Republicans not to nominate "someone who would simply give that issue away in the fall."

Santorum suggested it's not enough to defeat Obama. But that might be a tough sell with Republicans who say ousting the president is their top priority.

"We will no longer abandon and apologize for the policies and principles that made this country great for a hollow victory in November," he said.

Santorum, a Catholic with a strong record of fighting legalized abortion, criticized the Obama administration's bid to require Catholic-affiliated employers to cover birth control in their health insurance plans.

"He's now telling the Catholic Church that they are forced to pay for things that are against their basic tenets and teachings," he said. "It's not about contraception. It's about economic liberty."

Romney, Gingrich to address conference

Santorum spoke before Obama was expected to announce changes to his contraception policy.

In his remarks, the former senator called for far more exploration of domestic energy sources. Throughout the world, he said, "the more energy consumption, the higher the standard of living. That's just the bottom line."

Santorum made no obvious allusions to his other GOP rivals, Newt Gingrich and Ron Paul.

Romney and Gingrich were scheduled to address the CPAC crowd later Friday. The speeches come the day before Maine's caucus results will be announced.

Many Republicans expect Paul to do well there.