Politico reported on Monday that several Republicans, some of whom were willing to speak on the record, were frustrated by former President Donald Trump’s personal attacks on his new rival, Vice President Kamala Harris. One even called his behavior indicative of a “public nervous breakdown.”

That on-the-record Republican was Matthew Bartlett, a former Trump administration official who is now a Republican strategist. He was quoted as saying about Trump:

This is a guy who cut through the Republican primary like a knife through butter. This is a guy who pummeled a semi-conscious president in a debate and literally out of a race. And now this is a guy who cannot come to grips with a competitive presidential race that would require discipline and effective messaging. And we’re seeing a candidate and a campaign absolutely melt down.

Another GOP strategist who spoke on the condition of anonymity went through a laundry list of stumbles made by Trump since Harris entered the race, including Trump’s recent attacks on Georgia Gov. Brian Kemp (R) at a recent rally:

Democrats are racing to remake Kamala Harris from real life Selina Meyer into the female [Barack Obama] — and Donald Trump’s lack of discipline is letting them. Every day Trump swipes at shiny objects — attacking the popular governor of a swing state, questioning the race of his opponent, or battling cat lady comments by his VP — is a day he is letting Harris define herself on her own terms.

John Watson, a former Georgia Republican Party leader, told Politico: “Attacking Brian Kemp and his family is a galactic, unforced error.” Another Republican strategist from Tennessee said: “It’s just indicative of a total lack of focus on the point.”

While the Republicans Politico spoke to expressed a desire for Trump to stay on script and go after Harris’s policies and record, GOP strategist Barrett Marson said:

I think we are long past the time where we thought he could maybe rein in his worst angels and he’s going to keep doing this and no amount of polling data or advice from people close to him will change him. He’s a 78-year-old guy stuck in his ways. And this has been his way for decades.

Since Harris entered the race, polls have shown her closing the lead Trump had over President Joe Biden. Her campaign also vastly outpaced Trump’s in fundraising in the month of July, including record numbers during the month’s final ten days.