Rick Santorum talks to reporters during a visit to his campaign office in Grand Rapids, Michigan

Editor’s Note: William J. Bennett, a CNN contributor, is the author of “The Book of Man: Readings on the Path to Manhood.” He was U.S. secretary of education from 1985 to 1988 and director of the Office of National Drug Control Policy under President George H.W. Bush.

Story highlights

William Bennett: Romney won primaries, but Santorum still bullish on his prospects

Santorum says strong fundraising, organization stokes his sense of momentum, he writes

He says Santorum now steering message away from social issues and toward economy

Bennett: Romney still must reach conservatives; blue-collar voters favor Santorum

CNN  — 

Despite Mitt Romney’s victories in Arizona and Michigan on Tuesday, Rick Santorum is still bullish on his chances to win the Republican nomination.

In an interview Wednesday on my radio show, “Morning In America,” Santorum counted Michigan as a win of his own. “If you look at the entire state (of Michigan),” he said, “we won most of the counties. We won half of the congressional districts, which means we won half the delegates here.”

He went on to explain why he thinks Romney’s success isn’t what it seems to be: “I think the big reason we lost is because of early voting. About 100,000 votes were cast before Colorado, Minnesota and Missouri voted. If you look at the early voting, we lost very, very badly. On election day, we won overwhelmingly.”

Romney’s dominance in Arizona and resilient comeback in Michigan didn’t faze Santorum. “If you look at our money report for this time around, this month, we’re going to raise probably between $8 and $9 million in the month of February. I would be stunned if we didn’t out-raise Romney this month,” he said.

Money might not be the only thing growing for Santorum; enthusiasm also seems on the rise. While Romney relies on a few big-money donors, Santorum says he had more than 120,000 small-dollar donors in the month of February. Santorum’s support is building, and his organization is growing.

Looking ahead, Santorum hopes this momentum will carry into the all-important Super Tuesday contests. He predicts: “There are three or four states we think we can do exceptionally well in. We think we can do well in Ohio, which most of the polls have us in a small lead right now; Tennessee, which most of the polls have us in a fairly comfortable lead; and Oklahoma, which most of the polls have us in an even more comfortable lead.”

Santorum has been under heavy fire for his recent comments about college education, social issues and the separation of church and state. I asked him about the focus of his message going forward.

“Economic liberties as well as what we can do to create more jobs and opportunity – that’s the focus, and we’ll keep that focus,” he said.

Santorum should stay on this message. His sweep in Colorado, Minnesota and Missouri was largely a reflection of his blue-collar economic focus, not social issues.

His task becomes all the more difficult after Romney’s impressive week. Romney trounced Santorum across the board in Arizona and avoided catastrophe with a key victory in Michigan. His success comes on the heels of his strong performance in CNN’s Arizona debate and the unveiling of his new tax plan. For Romney, bolder is better, and that should be his takeaway going forward.

Yet, the usual doubts remain for Romney. He has yet to satisfy the broad swath of the conservative base. In Michigan exit polls, Santorum won “very conservative” voters by a 15-point margin and drubbed Romney by a 40-point margin with voters who want their candidate to be a “true conservative.” Instead of attacking his rivals’ records, Romney should focus on bolstering his conservative image, whether through policy proposals or attacks on the president’s record.

The true test comes in Ohio on Super Tuesday. No Republican has ever won the presidency without winning Ohio. It is a swing state symbolic of the major national political trends. The unemployment rate hovers around the national average, and there are both urban and rural areas still struggling to pull themselves out of the recession.

Ohio’s large block of blue-collar working class voters favors Santorum. Should he win Ohio, he will have won a majority of the Midwest (Colorado, Minnesota and Iowa). His campaign will roar back to life, and the nomination will not be settled anytime soon.

But Romney is in for the long run with resources, organization and proven resilience. Stay tuned. There is more to come next week.

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The opinions expressed in this commentary are solely those of William Bennett.