Former Trump-era adviser John Bolton warned this week that "mini-Trumps" risk "political suicide."
Bolton referenced how Trump-backed candidates like Dr. Mehmet Oz aren't doing well in their races.
"Trump's fixation on himself and the 2020 election are poisonous to independent and undecided voters," Bolton said.
Former Trump administration National Security adviser John Bolton warned this week that candidates who model themselves after the former president might risk "political suicide" in the midterms.
Bolton was commenting on a poll carried out by his organization, the John Bolton Super PAC. The poll said it surveyed 1,200 likely voters in Pennsylvania, Ohio, North Carolina, and Georgia from July 22-23.
The Bolton PAC concluded from its poll data that Trump was becoming a "significant drag on the general-election prospects" of GOP candidates. The PAC cited in particular the Trump-endorsed Dr. Mehmet Oz and JD Vance - both of whom are flagging in their races - highlighting how undecided voters surveyed did not favor Trump.
"These results do not mean Republican candidates should not campaign as true conservatives, only that they stress their loyalty to principles," Bolton said in a statement.
"We can still win these races, but the candidates need to separate themselves from Trump," he added.
Bolton warned that Trump's influence on the nominating process and the role that he might play in swaying how the midterms go could be "fatal to GOP efforts to gain outright control of the Senate."
"Trump's fixation on himself and the 2020 election are poisonous to independent and undecided voters," Bolton said in his statement.
"Republican candidates who hope to win in November are risking political suicide if they stress their closeness to Trump, or allow their opponents to portray them as mini-Trumps," he added.
Bolton's warning comes amid rumblings that Trump's high-profile Senate picks - Oz, Vance, and Herschel walker - might lose their races despite headwinds for the Democratic Party.
In particular, recent polling showed that Democratic candidate John Fetterman has now pulled ahead of the Trump-backed Oz in his race. Oz and Fetterman are slated to face off in November to determine who will replace retiring GOP Sen. Pat Toomey in Pennsylvania.
The Washington Post reported in April that sources close to Trump feared that the former president's risky endorsements of Oz and Vance could risk his reputation as the Republican kingmaker.
Trump's post-presidential press office and representatives for Oz and Vance did not immediately respond to requests for comment from Insider.