With less than a month to go until voting on Nov. 4, U.S. Sen. Mary Landrieu has replaced her campaign manager and added some veteran aides, as she tries to win a fourth term in a tough contest against a well-financed Republican challenger in an overwhelmingly Republican state.

An 11th-hour shake up of a campaign can signal panic or desperation, or at least dissatisfaction with the candidate’s election operation to date, but the Landrieu staff portrayed the moves as business as usual for Landrieu, D-La. She has routinely brought in seasoned staffers to close the deal in previous elections, as well, the campaign said.

“Like any of the senator’s winning campaigns, we are tightening our senior strategy team and bringing on some of her longtime advisers to help out during the last month of the race,” a campaign spokesman said Wednesday.

Polls consistently have shown Landrieu short of the majority she needs to win re-election in the Nov. 4 open primary. They indicate she will be forced into a Dec. 6 runoff with her leading Republican challenger, U.S. Rep. Bill Cassidy, of Baton Rouge — even though she has raised and spent more campaign money than Cassidy and has received more backing from outside groups making independent expenditures on political advertising.

A second Republican candidate — retired Air Force Col. Rob Maness, a tea party favorite — appears to be drawing enough support from Cassidy to keep him from a win Nov. 4. But a head-to-head matchup with Cassidy Dec. 6 could prove daunting for Landrieu in a state that went Republican 58-41 in the 2012 presidential election and in which Landrieu is the lone remaining Democrat elected statewide.

Because of those factors, the Republican Party nationally has targeted Landrieu in its effort to pick up the six seats it needs to gain a Senate majority in the fall elections. Conservative political groups are already lining up to pour money into a runoff in support of Cassidy.

Landrieu, though, has overcome long odds before: She was re-elected without a runoff in 2008, when Louisiana went even more heavily Republican in presidential voting.

Displaced as Landrieu’s campaign manager for this election is Adam Sullivan, although he will stay on as an adviser, the campaign said. Taking over for him is Ryan Berni, manager of the successful February re-election campaign of New Orleans Mayor Mitch Landrieu, who is the senator’s brother. Berni is a former chief of staff for James Carville, the legendary Democratic political operative from Louisiana now on the faculty at Tulane University in New Orleans.

Also joining Landrieu is New Orleans political consultant Norma Jane Sabiston, a longtime family friend who has served as a senior advisor on previous Landrieu senatorial campaigns and worked as chief of staff in the senator’s Washington office years ago. Sabiston has played an informal role for this election, the campaign said, but now will join the effort full-time as an unpaid volunteer.

T. Bradley Keith, who has served on Landrieu’s senatorial staff as state director since her first term in Congress, is taking a leave from that government job to work on the campaign. Matt Lehner, communications director for Landrieu’s Senate office, made that transition earlier.