NASHVILLE (AP) - The sudden flurry of presidential campaign activity in Tennessee comes to a close Tuesday when voters cast their ballots in the Republican primary.

After a fairly sleepy campaign season - early voting was down 37 percent compared with 2008 - activity suddenly ramped up in the last week as the front-runners each held rallies around the state with hopes of landing a key victory in the South.

Former Massachusetts Gov. Mitt Romney made his first public appearance in the state at a rally in Knoxville on Sunday, while former Pennsylvania Sen. Rick Santorum made his latest campaign stops at Memphis-area churches earlier in the day.

Meanwhile, former House Speaker Newt Gingrich headed for Kingsport, Knoxville and Chattanooga on Monday.

Republican operative Josh Thomas, a Romney supporter, said Santorum's focus on religious and social issues may come as an advantage in Tennessee. Former Arkansas Gov. Mike Huckabee won th e state's Republican primary in 2008 on a similar platform, while Romney came in third.

"So that bodes well for Rick Santorum's brand of conservatism and economic populism," Thomas said.

But Thomas cited Romney's superior organization this year, as well as the endorsements of several prominent state Republicans, like Gov. Bill Haslam, U.S. Sen. Lamar Alexander and state House Speaker Beth Harwell.

"Tennessee's primary will be closer than most anticipate," Thomas said.

Bob Davis, a former state Republican Party chairman, said endorsements will only take a candidate so far.

"Tennesseans are independent-minded thinkers, they don't necessarily like people to tell them how to vote," he said. "They've gone against the grain a few times, and I think Tuesday will be really interesting."

At a Santorum rally outside Knoxville last week, Anderson County teacher Parker Stanley said the former senator carries the least political and personal baggage amo ng the candidates.

"They're trying to say he's a rightist Christian," he said. "And I don't think that will be as damaging as what they can say against Romney, or about Gingrich."

State Rep. Bill Dunn, a Knoxville Republican and Santorum supporter, downplayed Romney's fundraising advantage and his endorsements from the GOP establishment.

"People are not going to be influenced so much by the money, but by the principles of the man," Dunn said. "So that's a plus for Santorum."

But at Haslam-led rally for Romney in Memphis last week, voters said they like Romney's past business experience, saying it will help lead the country out of sluggish economic times.

Memphis restaurant owner Tom Powers said Romney showed he could turn around "something that was headed in the wrong direction" with his work during the Salt Lake City Olympics. He called Romney fiscally sound and said the economy is the most important issue for him.

"He can work with Republ icans and Democrats and actually build a consensus and get done what we need to do," said Powers, 33. "Come general election time, that will make him a stronger candidate."

Meg Crisp, a Nashville accountant who attended the Memphis rally, said she backs Romney because he is most focused on the economy.

"A lot of Southern voters love all that Christian rhetoric," said Crisp, 55. "We're not electing a radio talk show host. If we were, I think Gingrich would be a good person. We're also not electing a pastor, we're electing the president of the United States.

"I personally think the separation of church and state is a really good thing," she said. "I want a president, not a pastor."

But Crisp noted that connecting with the average voter is a challenge for Romney.

"He needs to get better at it, for sure," she said.

After the rally Haslam acknowledged Santorum's charisma and ability to connect with voters.

"Santorum does have a personality that fits," the governor said. "But the more time people spend around (Romney), the more they like him."