GRAND RAPIDS, Mich. – Rick Santorum is in a frontrunner state of mind.

The former senator from Pennsylvania and GOP presidential candidate on Monday night delivered brief remarks at the Kent County Republican Party Lincoln Day Dinner in which he made no mention of his rival for the White House nod, former Massachusetts governor Mitt Romney (R).

“Obviously, this has been quite a rollercoaster ride for us, and things are going well for us,” Santorum told the roughly 700 Republicans gathered in the ballroom of the tony Amway Grand Plaza Hotel in downtown Grand Rapids. “We’re out and we’re talking about a positive message. We’re out there talking about the important things that’re on people’s minds in America today.”

Accompanied onstage by several of his children and his wife, Karen (“my sweetheart of 21 years, the mother of our children, and the rock on which I stand”), Santorum spoke for less than eight minutes and touted his “positive, hopeful vision for America.” He also cast the race as a two-man contest between himself and President Obama.

“’Whose side is he on?’ is the question,” Santorum said of Obama. “We need someone who’s on your side.”

He criticized Obama’s energy policy, blasting the White House for rejecting a permit for the Keystone XL oil sands pipeline.

And he urged the assembled Republicans to choose a candidate that can create the sharpest contrast with the president in the fall.

“You have an opportunity here in conservative western Michigan to talk and speak loudly about what this country needs,” Santorum said.

Santorum received a standing ovation at the end of his speech, but it was a far more subdued reaction than he has received at previous local GOP gatherings in recent days, particularly the Lincoln Day dinners in Akron and Georgetown, Ohio, over the weekend.

The event comes as Santorum is leading Romney in the Michigan polls but also as the former senator has caused a media firestorm with some of his campaign-trail remarks in recent days.

At a Saturday event in Columbus, Ohio, he accused Obama of believing in a “phony theology” that is not based on the Bible, and at a Georgia megachurch Sunday night, he drew a provocative comparison between the country’s current mood and America’s hesitance to enter into World War II.

Asked Monday night whether he was comparing Obama to Adolf Hitler in his remarks, Santorum shook his head.

“No,” he said with a smile before heading into a private meeting with Michigan GOP elected officials.

“Oh my goodness,” Karen Santorum said in response to the question.

While Santorum was the featured speaker Monday night, the Romney camp had a presence, too.

The candidate’s brother, Scott Romney, was seated a t a table toward the back of the ballroom. Freshman Rep. Bill Huizenga (R-Mich.), who has endorsed Romney and spoke on his behalf in a conference call earlier Monday, acknowledged Scott Romney from the podium.

Huizenga noted that he had spent the eve of the New Hampshire primary together with the Romneys backstage.

“I’ve got to tell you, I spent a little time out in New Hampshire with the family, right before that primary campaign ... and you really do see the character of people when you’re backstage,” he said.

“At the top of that list (of people with character) I put the Romney family,” Huizenga said to applause.

Also present at the Monday night event was Virginia Gov. Bob McDonnell (R), who addressed the crowd later in the evening.