Rick Santorum and his wife, Karen, check out a cheese hat as he courts conservative… (Scott Olson, Getty Images )
MENASHA, Wis. — If Rick Santorum was weighing whether to abandon his quest for the presidency on Monday, the eve of the Wisconsin primary that could effectively crush his campaign, he worked hard not to show it.
On a day packed with rallies, some bowling and a sampling of squeaky cheese curds, Santorum was looking ahead not just to the next round of Republican presidential primaries, but also to a possible floor fight against front-runner Mitt Romney at the party's national convention in August.
"I think it would be a fascinating display of open democracy," Santorum told reporters at a cheese shop in Appleton. "And I think it would be an energizing thing for our party to have a candidate emerge who isn't the blessed candidate of the Republican establishment."
The shorter the fall campaign against President Obama, the better for Republicans, he said. "If I thought that prolonging this race was a detrimental thing for our chances to win in the fall, I may — I would take a different course.
"But I don't."
Santorum's defiant pose reflected the crucial juncture his campaign has reached. The odds are stacked so heavily against him in the battle against Romney that Wisconsin's primary stands as a potentially lethal test of Santorum's capacity to survive.
He has vowed to keep campaigning if he loses Wisconsin. But Romney, a former Massachusetts governor already widely seen as the presumptive nominee, would be viewed that way even more with a Tuesday victory — and potential wins in Maryland and the District of Columbia as well. That would dry up potential donations to Santorum and intensify the pressure to drop out. In a sign of Santorum's fading relevance, Obama's reelection campaign began TV advertising against Romney on Monday.
For Santorum, who clawed his way into contention with months of dawn-to-dusk stumping across Iowa on a budget fit for a college student, there is a big personal dimension to the campaign's next phase; the prospect of giving up is something akin to heartbreak.
With his improbable rise from the bottom ranks of a crowded field of GOP candidates, Santorum has come to personify the restless faction of tea party conservatives who upended the Republican establishment and fueled huge GOP victories across the nation in 2010, notably in Wisconsin. Santorum has also succeeded in uniting conservative evangelical Christians who have long shunned Romney, a feat none of his other rivals managed to achieve.
On Monday, Santorum sought to rally conservatives in Wisconsin's Fox Valley with scathing attacks on Romney's mixed record on guns and abortion. At Sabre Lanes, a bowling alley here on Lake Winnebago, the former senator from Pennsylvania reminded more than 100 supporters about his A+ rating from the National Rifle Assn. and his opposition to the 1990s federal ban on assault weapons.
"I stood tall, and I didn't say that we have a lot of good gun laws in Massachusetts and I wouldn't touch any of them," Santorum said.
He criticized his rival not only for state funding of abortion during his tenure as governor, but also for a $150 donation that Romney's wife, Ann, made to Planned Parenthood in 1994. Santorum did not mention her by name.
"Gov. Romney's actually running ads out there right now suggesting that I'm not pro-life, where Gov. Romney and his family have contributed money to Planned Parenthood," he said.
Gesturing toward his wife, Karen, Santorum mentioned that she had home-schooled their seven children. He also took on the cadence of a Sunday school instructor as he asked, "Why is it that all men were created equal? Because they were endowed by their …"
"Creator," the crowd shouted in unison, quoting from the Declaration of Independence.
"With certain inalienable rights," Santorum concluded to a burst of cheers.
Paying homage to Wisconsin's besieged Republican governor, Scott Walker, who is facing a recall election in June, Santorum drew a comparison to his own commitment to conservative ideals.
"You elect someone with strong convictions, strong principles, you put them in office, sometimes they surprise you and actually stand by those principles and get things done," he said.
Santorum closed his Wisconsin campaign the same way he opened it 10 days ago — with an appeal to the culturally conservative blue-collar voters most apt to bristle at Romney's upper-class bearing.
In Menasha, he went bowling, a frequent highlight of his Wisconsin travels. At Simon's Specialty Cheese in Appleton, Santorum joined the kitchen staff in making grilled cheese sandwiches.
"Perfect — you're hired," store manager Mary McCauley told him.
Standing among yellow foam cheesehead hats in the shapes of sombreros, firefighter helmets and the wedges worn by football fans at Green Bay Packers games, Santorum said in front of a cluster of news cameras that he was resonating with "folks who are struggling to make ends meet."
His spokeswoman, Alice Stewart, echoed Santorum's contention that there remained a viable path to the nomination, starting in Pennsylvania, which votes April 24. But at some point, she said, "We may possibly have a discussion about him being a vice presidential candidate."