Former White House national security adviser John Bolton reiterated Friday that he may run for president in 2024—adding that he can beat his old boss, former President Donald Trump, to the Republican nomination because of the “terminal decline” in the 45th president’s support, The New York Post reported.

“I wouldn’t run as a vanity candidate. If I didn’t think I could run seriously then I wouldn’t get in the race,” the 74-year-old Bolton told ITV’s “Good Morning Britain.”

“I would get in to win the nomination and I would do it primarily on the basis that we need a much stronger foreign policy,” added Bolton.

Bolton told the British broadcaster that he specifically wants to derail Trump, who has called his onetime subordinate a “liar,” a “dope,” and “a disgruntled boring fool.”

“I think Trump’s support within the party itself is in terminal decline,” Bolton said of the backlash against the US former commander-in-chief.

Trump fired Bolton in September 2019 after the then-president reportedly clashed with the longtime diplomat on issues related to North Korea and Afghanistan.

Now, Bolton believes his tough-guy stance on foreign policy is what will give him the upper hand in a possible presidential race.