BATON ROUGE, La. — Democratic Sen. Mary Landrieu and Republican Rep. Bill Cassidy spent Friday working to secure support from their core constituencies as they prepared to face off one last time in Saturday’s hotly contested Senate runoff election.

Landrieu campaigned across south Louisiana in Lafayette, Baton Rouge, St. Rose and her home town of New Orleans. Democratic surrogates supporting her campaign — including former Denver Mayor Wellington Webb and Max Richtman, president and CEO of the National Committee to Preserve Social Security and Medicare — represented her at other locations.

Cassidy campaigned in Lake Charles and Metairie with Sen.-elect Joni Ernst, R-Iowa, before returning to his home in Baton Rouge.

Landrieu told a Women for Mary gathering at a packed downtown Baton Rouge restaurant that Cassidy was “hiding from his own record because he does not have one. If I had a record like his, I’d be ducking, too.”

Louisiana Republican Sen. David Vitter told Cassidy supporters in Metairie he’s “sure as heck ready” for the day when Landrieu won’t be around to cancel out his vote on issues such as repealing the 2010 Affordable Care Act.

Cassidy said he’s expecting to win but is taking nothing for granted, so his voters shouldn’t, either. He said “Louisiana is going to be the exclamation mark” on the Nov. 4 election that gave Republicans control of the Senate, beginning next year.

“But you don’t become an exclamation mark by winning 51 (%) to 49 (%). You become an exclamation mark by, BOOM!” he shouted.

Landrieu faces long odds in the runoff election. Her best chance for an upset depends on heavy turnout among black voters, one of her core constituencies. But early voting results show that’s unlikely. Nearly 17,600 fewer black voters cast early ballots ahead of the runoff than voted early before the Nov. 4 election.

A win by Cassidy would give Republicans their 54th seat in the Senate, beginning next year. Democrats would control 46 seats.

No Senate candidate took more than 50% of the vote on Nov. 4 in Louisiana, setting up Saturday’s runoff. Landrieu took 42.1% and Cassidy took 41%. A second Republican on the ballot, Rob Maness, took 13.8%.

Cassidy, 57, a physician and former Republican state senator who donated money to Democratic candidates, including Landrieu, well before entering politics, is expected to win support on Saturday from voters who had backed Maness.

He has long been considered the frontrunner in the race, thanks largely to Louisiana’s increasingly conservative tilt and deep dislike for President Obama. Cassidy’s campaign has repeatedly tied Landrieu to Obama.

“I suspect the Republicans are using the same playbook for the runoff: Convince more of the white working class that their interests are being threatened by Obama and the Democrats,” said Rickey Hill, head of the political science department at Jackson State University.

Former Senate majority leader Trent Lott, of Mississippi, a Republican, said Obama’s unpopularity worked heavily against Landrieu.

“In states like Mississippi, Alabama, Louisiana and North Carolina, if you’re with Obama you’re out,” he said recently.

Landrieu has highlighted issues where she’s parted ways with the president, including her opposition to the administration’s moratorium on deep-water drilling after the 2010 BP oil spill, and her support for the Keystone XL pipeline.

But Hill said those efforts may have backfired with some African-American voters.

“Strategically, Landrieu has made missteps she might not be able to overcome,” he said.

At least two-dozen current and former congressional lawmakers have traveled to Louisiana to campaign with either Landrieu or Cassidy. And members of Congress have contributed hundreds of thousands of dollars to the campaigns.

That help was essential for Landrieu, the Democratic Party’s only remaining elected statewide official in Louisiana. She was largely abandoned by national Democratic party committees after Nov. 4 and has been seriously outspent by Cassidy and his supporters during the runoff.

Mike Hasten is Gannett’s Louisiana statehouse reporter. Deborah Barfield Berry reports for USA TODAY’s Washington bureau.