John Bolton, who served as national security adviser to former President Donald Trump, said Monday that Trump’s candidacy and his suggestion that the Constitution be terminated to put him back in office has led him to consider launching a presidential campaign.

Appearing on NBC News’ Meet the Press Now, Bolton called Trump’s run for office “an existential threat” to the nation.

“He has said that he wants the Constitution terminated. Now he’s tried to walk it back today, but he failed… He is saying the same thing in slightly different words. It is not merely wrong and outrageous. It is disqualifying.”

Bolton added that he’s also concerned by top Republicans who do not forcefully condemn the former president. Regarding potential GOP presidential candidates, Bolton said that before they enter the race, they “should say, ‘Donald Trump is wrong, we repudiate him, [and] he doesn’t belong in the Republican Party.’”

“And honestly, if they don’t, there is one thing that would get me to get into the presidential race…it would be to make it clear to the people of this country that Donald Trump is unacceptable as the Republican nominee,” Bolton said.

“I would like to see Shermanesque statements from all the potential candidates,” he added when asked when specifically would lead to him putting his hat in the ring. “If I don’t see that, I’m going to seriously consider getting in.” Bolton reiterated that sentiment in a tweet Monday afternoon.

After resigning from the Trump administration in September 2019, Bolton penned a memoir depicting his former boss as “stunningly uninformed on how to run the White House, let alone the huge federal government.”