Donald Trump’s recent comments about abortion as a political issue show the former president has lost his ability to read Republican voters, a veteran Trump campaign insider said.

In messages seen by the Guardian, the operative said: “Trump has no political skills left. His team is a joke. The ship is sinking.”

Trump kicked off his latest scrap with his own party on his Truth Social platform on Sunday, saying: “It wasn’t my fault that the Republicans didn’t live up to expectations in the midterms.”

On the contrary, most observers suggest Trump’s refusal to admit defeat in 2020 and endorsement of backers of his election fraud lie contributed to Republican disappointments in November, including barely scraping a House majority, failing to take the Senate and losing key races in battleground states.

Trump said: “It was the ‘abortion issue’, poorly handled by many Republicans, especially those that firmly insisted on no exceptions, even in the case of rape, incest, or life of the mother, that lost large numbers of voters.”

In this instance, most observers would agree. It is generally held that Dobbs v Jackson, the supreme court ruling handed down in June which ended federal abortion rights, had a tangible effect at the ballot box.

Trump also complained that “people that pushed so hard, for decades, against abortion, got their wish from the US supreme court and just plain disappeared, not to be seen again”, and said the Republican leader in the Senate, Mitch McConnell, had been “stupid” in how he spent campaign cash.

The comments prompted criticism from the political right.

The Fox News contributor Ben Domenech said it was “hard to express how many false things Trump says in this one ‘truth’”.

He listed stringently anti-abortion Republicans who won, contested Trump’s claim that candidates supported no-exception bans and said Trump should have spent his own money to boost candidates such as Kari Lake, the election denier defeated for governor in Arizona.

Pointing to a 2024 primary in which Trump is the only declared candidate but has slipped in polling, in part due to legal exposure for election subversion and his business affairs, Domenech added: “Trump betraying the pro-life cause on Dobbs has been telegraphed for a long time and is a huge opening to bash him in the 2024 stakes which I expect several candidates to seize.

“Finally, think how stupid it is for Trump to run left on the pro-life issue. This is the biggest win of his presidency. Huge vested goodwill from pro-lifers. And what does he do? Call them quislings and say they’re too radical! Very dumb.”

Trump appointed three hardline conservatives to the court which ended abortion rights. But his own views have long been questioned and even in 2016, in his successful run for the White House, he struggled to follow a consistent line.

Back then, Trump was asked – by a New York Times reporter – if “when he was a swinging bachelor in Manhattan, was he ever involved with anyone who had an abortion?”

Trump said: “Such an interesting question. So what’s your next question?”

Six years later, the messages from the veteran operative about Trump’s abortion remarks pointed to a widening perception that the ex-president’s 2024 candidacy is in danger of falling apart a year before the primary.

Last month, after New York Magazine portrayed a “sad, lonely, thirsty, broken, basically pretend run for re-election”, Trump disputed the reporting and called the reporter, Olivia Nuzzi, “a shaky and unattractive wack job”.

The Trump insider said Nuzzi’s piece contained “some accurate stuff”.