Former U.N. Ambassador Nikki Haley defended her past support of Donald Trump while deepening her criticism of her main rival for the GOP nomination, arguing that the former president is “more diminished than he was.”

In an interview Tuesday with “TODAY” co-host Craig Melvin, Haley made a generational argument for her presidential candidacy, swiping at both Trump and President Joe Biden to argue that they are both “diminished.” And she justified her past support for Trump, during both his two previous presidential campaigns and her service in his administration, by saying he has changed since then.

“During the time that I was in the administration, I called him out every single time,” Haley said, arguing that her past support for Trump wasn’t unconditional. “If something was wrong — I had a conversation with him about Charlottesville, I had a conversation about something that he would say about women, I had a conversation with him about multiple things.

“The problem now is he is not the same person he was in 2016,” she continued. “He is unhinged; he is more diminished than he was, just like Joe Biden’s more diminished than what he was.

“We have to see this for what it is,” Haley added. “This is a fact: He is now saying things that don’t make sense.”

Both Haley and Trump have turned the temperature up as she looks to mount a come-from-behind victory in the GOP presidential nominating fight — and Trump looks to end the contest.

In recent weeks, Haley has repeatedly called Trump “unhinged,” accused him of cozying up to Russian President Vladimir Putin, criticized him for confusing her with former House Speaker Nancy Pelosi and declared him “not qualified” to serve as president, among other criticisms.

But her comments Tuesday were among her bluntest yet, as she warned against a potential campaign she characterized as one between a former president who could no longer handle the job and a current president who can’t, either.

“You’ve got Joe Biden, where the special counsel said he was diminished, and he’s not the Joe Biden he was two years ago,” Haley said. “You’ve got a Donald Trump who’s unhinged, and he’s more unhinged than he ever was. And why are we settling for that when the country is in disarray and the world is on fire?

“We don’t want these two old men running. We want someone who’s going to go and fight for us and work for us, with no drama, no vendettas.”

Haley’s justification, that the Trump running now is different from the one she used to support, is also an attempt to explain how she moved from serving in Trump’s Cabinet and defending him from past criticism.

She cited reporting that Trump called fallen soldiers “losers” and “suckers” as she castigated him as someone who didn’t respect the military.

But in 2020, she called on Biden to take down a tweet citing those comments because “all of us who worked with [Trump] witnessed the tremendous amount of love and respect he has for our military. He was determined to protect them.”

Throughout the interview, Haley repeatedly cited Americans’ discomfort with Biden and Trump, sentiments borne out across a slew of polling, including NBC News’. But the totality of polling also shows Trump well ahead of Haley in the GOP nominating fight, both in Haley’s home state, South Carolina, the next state with a high-profile nominating contest, and across the country, where the election will shift in early March.

In the middle of a campaign swing through her home state, Haley repeatedly pushed back against the idea that Trump’s victories in the first three nominating contests and her position in the polls signal Trump is on a glide path to the nomination.

“We’re going to be competitive in South Carolina, then we’re headed to Michigan, then we’re headed to Super Tuesday,” she said.

“We don’t pick kings. We don’t do coronations. We have a democracy where people vote,” Haley continued before adding, “Why would I get out as long as we keep it competitive?”

Haley talked up her performances, saying: “Don’t discount that I defeated a dozen fellas. Don’t discount that I ended up with 20% in Iowa when y’all said I wouldn’t make it. Don’t discount that I got 43% New Hampshire, and don’t discount me now.

“I’m doing this because we have a country to save,” she added. “I’m not doing this for my political career. I’m not doing this for any sort of gig. I’m doing this because our country deserves better. And I’m not going to stop fighting until I know I’ve done everything I can to save her.”

While Haley was critical of primary polls showing her trailing Trump, she pointed to polling that shows her performing better against Biden than Trump in a hypothetical general election. And Haley criticized the idea that staying in would only sap Republican resources that could be used to help defeat Democrats in the fall.

“Resources, from a man who spent $50 million of his own campaign contributions on his personal court cases, where the RNC is broke — I’m the one hurting the resources?” Haley said.

“If the Republican Party wants to be saved, I’m the one that saves the Republican Party,” she continued.

As a condition for appearing in the Republican National Committee’s sanctioned debates, Haley and the other GOP candidates signed pledges to back the party’s eventual nominee. And during the first debate, Haley raised her hand when the Fox News moderators asked who would still support Trump if he won the nomination but was “convicted in a court of law.”

Pressed about how she squares her comments that Trump is “not qualified” to serve as president with her pledge to support him if he wins the nomination, Haley quickly reiterated her pledge before she pivoted to criticizing Trump’s electability.

“Every Republican nominee signed a pledge before they could even get on the debate stage that said if we were not the nominee, would we support the nominee. And I said yes, and I stand by that,” Haley said.

At the same time, she went on, “I know the American people are not going to vote for a convicted criminal.”