By Gram Slattery

WASHINGTON Republican U.S. presidential candidate Ron DeSantis has replaced his campaign manager, a spokesperson said on Tuesday, as the Florida governor tries to reboot his flagging bid to overtake front-runner Donald Trump in the race for his party's 2024 nomination.

Generra Peck, a longtime DeSantis aide, will be replaced by James Uthmeier, another close advisor, said Andrew Romeo, the campaign's communications director.

The move comes four days after the biggest individual donor to a group supporting the DeSantis candidacy told Reuters he would not donate more money unless the pugilistic populist attracts more donors and adopts a more moderate approach.

The DeSantis campaign also made significant staff moves in July, cutting over a third of its staff and reshuffling some middle- and upper-level management.

"James Uthmeier has been one of Governor DeSantis' top advisors for years and he is needed where it matters most: working hand in hand with Generra Peck and the rest of the team to put the governor in the best possible position to win this primary and defeat Joe Biden," Romeo said in a statement.

DeSantis is running second in the race for the Republican nomination to face Democratic President Joe Biden in the November 2024 election, but has been sinking in opinion polls for months. The latest Reuters/Ipsos poll put his national support at just 13%, far behind former President Trump, with 47%.

Also joining the DeSantis campaign will be David Polyansky, who had a senior role at the main outside spending group supporting DeSantis, according to one person with knowledge of the matter, speaking on condition of anonymity.

DeSantis faces a crucial moment on Aug. 23 in Milwaukee at the first Republican debate of the 2024 campaign. Trump has said he plans to skip the debate, which would make DeSantis the focus of attacks from other candidates.

(Reporting by Gram Slattery; Editing by Scott Malone and Will Dunham)