Former Arkansas Gov. Mike Huckabee sought Alabama's most conservative votes Saturday as he told crowds in churches of his stand against abortion, and Arizona Sen. John McCain tried to ease the concerns of conservatives questioning his ability to unite the Republican Party. Saturday was the busiest day of campaigning yet leading up to Alabama's presidential primary, with former President Bill Clinton also stumping across the state for his wife.

In Tuscaloosa, Huckabee drew loud applause at Open Door Baptist Church when he declared, "I am pro-life."

"If it costs me the election, so be it," Huckabee said.

Huckabee and actor Chuck Norris also spoke at Church of Christ-affiliated university in Montgomery and at a Methodist church in Huntsville, the same city where Clinton told a cheering crowd at a high school gym that his wife is the Democrat best suited to fix the ailing economy.

Clinton also made an afternoon stop at Miles College in Birmingham, while McCain rallied with his supporters at a downtown hotel.

Aides said former Massachusetts Gov. Mitt Romney would make a speech in Birmingham on Monday on the eve of the Super Tuesday primary, with Alabama one of 24 states holding primaries or caucuses.

McCain, who was making a campaign swing through Tennessee and Alabama, addressed concerns raised by talk show host Rush Limbaugh, author Ann Coulter and some other conservatives about whether he can unite Republicans if he's the nominee.

"I believe that the majority of the Republican Party conservatives are convinced that I'm the best equipped to lead this country, unify our party and take on the challenge of radical Islamic extremism," he told reporters.

McCain said he had a 24-year record in the Senate of "fighting for the rights of the unborn" and boasted that he never asked for a single earmark or pork barrel project for his home state of Arizona.

In Birmingham, he told a crowd of more than 800 people that the Senate must pass the president's economic stimulus package, make President Bush's tax cuts permanent and cut the corporate tax rate.

In Tuscaloosa, where the crowd filled about half of the 1,500-seat sanctuary of Open Door Baptist Church, Huckabee hit on hot-button conservative issues: illegal immigrants, the income tax and government spending.

"I'd like to be the president who nails the `going-out-of-business' sign on the front door of the IRS," he said. Huckabee has proposed replacing the income tax with a sales tax.

He called for tougher border security and took jabs at McCain and Romney without mentioning his GOP opponents' names.

"You really would like to get a president to agree with himself on some issues," Huckabee said, a dig at Romney's changed position on abortion.

He said spending is out of control in Washington, and in a swing at McCain added: "It doesn't make sense that someone would be sent to the White House who has a Washington address."

McCain, however, sounded the same theme in Birmingham, saying spending in Washington is "out of control."

"We have to stop it," he said to strong applause.

On McCain's Deep South swing, he sought to pick up Republicans who had been supporters of former Tennessee Sen. Fred Thompson, and he did that in Birmingham. Alabama Senate Minority Leader Jabo Waggoner, R-Vestavia Hills, who had been running as a Thompson delegate, attended the rally.

McCain was accompanied by state Attorney General Troy King and U.S. Rep. Spencer Bachus, R-Birmingham, who were early supporters.

Huckabee was joined on his Alabama trip not only by actor Chuck Norris, but by bass fishing legend Ray Scott and Republican state Sens. Charles Bishop of Jasper and Hank Erwin of Montevallo.

Huckabee announced during his Alabama swing that he had agreed to support the immigration plan proposed by U.S. Sen. Jeff Sessions, R-Ala., which includes construction of a border fence and requiring a fingerprint-encoded identification card for all foreigners authorized to work in the U.S.

Sessions, who was not with Huckabee, issued a statement saying: "It's been 40 years since we've had a president committed to enforcing our immigration laws. ... With his commitment today, Governor Huckabee demonstrates that he is serious about ending illegal immigration and creating a lawful system that serves the long-term interests of our country."

Huckabee was making his second visit to Alabama in eight days. Susan Fillippeli, a Republican political consultant who teaches a course at Auburn University on "presidential campaign rhetoric," said Huckabee has to do well Tuesday in the Southern primaries of Alabama, Georgia, Tennessee and his home state of Arkansas.

"If he doesn't, that ends any chance he's going to do well nationally," she said.

Recent statewide polls in Alabama have shown Huckabee and McCain in a tight race among Republicans. On the Democratic side, the race between Clinton and Obama could be decided by voters making a late choice before Tuesday.

Some at the Tuscaloosa rally said Huckabee's conservative political stands, not his religion, drew them to his side. But Stephen Hoyle, a 20-year-old security technician from Tuscaloosa, said he is a Southern Baptist and was attracted by Huckabee's background as a Baptist minister.

"He's got a Christian view and talks about low-class people rather than upper-class people. He's down-to-earth," said Hoyle.

Speaking to a crowd of as many as 2,000 in the Huntsville High School gymnasium, Clinton said Hillary Rodham Clinton's time in the Senate proved she could make progress creating new jobs, improving education and restoring America's international standing.

"No one else has such a good record of passing bills with Republicans," Clinton said during an hourlong talk. "If you want a change agent, Hillary is your candidate and you should support her!"

Clinton supporters sat on plastic bleachers holding up blue campaign signs as her husband spoke on a stage on the gym floor.

Clinton never mentioned Democratic contender Barack Obama by name, but he said he was "amused" by criticism during a recent debate that a vote for his wife would be "a step into the past."

"The 90s weren't too bad. They look pretty good compared to what we've got now," the former president said to cheers.