WASHINGTON (AP) - A jubilant Rick Santorum is leveraging victories in Colorado, Minnesota and Missouri to increase pressure on Mitt Romney, labeling him "a well-oiled weather vane" who often shifts his positions.

Santorum tells CNN Republican conservatives "are beginning to get it" that he's best equipped to take on President Barack Obama.

The former Pennsylvania senator acknowledges Romney has a substantial advantage in political fund-raising, but says, "We feel like going forward we're going to have the money we need to make the case we want to make."

Santorum said Romney "had a great career in the private sector, but we're not running for CEO of the country. We're running for someone who can lead the country."

He told MSNBC he's not "looking for folks in Washington, D.C., to affirm our campaign."