Maureen Groppe | USA TODAY

USA TODAY

WASHINGTON – A new poll shows that only four in 10 Republicans believe President Donald Trump talked to the Ukrainian president about investigating political rival Joe Biden, even though Trump has acknowledged doing so.

That compares with 85% of Democrats and 61% of independents surveyed by Monmouth University Poll who said Trump "probably did" mention the possibility of an investigation into the Biden family during a July phone call with Volodymyr Zelensky.

"This seems to be another example of partisan tribalism at work in public opinion,” said Patrick Murray, director of the independent Monmouth University Polling Institute.

The national survey was conducted Sept. 23-29, as the Ukraine story evolved.

Trump has repeatedly, without evidence, claimed that Biden as vice president tried to stop an investigation into a Ukrainian energy company where his son Hunter served on the board of directors.

Trump directly acknowledged on Sept. 22 that he spoke with Zelensky about Biden, four days before the White House released a summary of the call. According to that reconstruction of the conversation, Trump told Zelensky there was "a lot of talk" about Biden's son's activities in Ukraine and that he was directing his personal attorney Rudy Giuliani and Attorney General William Barr to assist in the inquiry “to get to the bottom of it.”

"A lot of people want to find out about that so whatever you can do with the attorney general would be great,” Trump said.

Chris Kleponis. epa-efe

Trump maintains there was nothing improper about that conversation. But its disclosure prompted House Speaker Nancy Pelosi to launch an impeachment investigation into whether Trump abused his authority by using his office for personal gain.

Democrats question whether Trump used congressionally approved military aid intended for Ukraine as leverage to push for an investigation of Biden.

More than six in ten of all adults surveyed by Monmouth said it is not appropriate for a U.S. president to make the type of request of a foreign leader that Trump did. But only three in ten Republicans agreed with that statement.

And while about half of all adults (49%) said it's a good idea for the House Judiciary Committee to conduct an impeachment inquiry, less than half (44%) said Trump should be impeached and compelled to leave the White House.

The public is divided on the veracity of Trump's claim that Biden pressured Ukrainian officials to keep them from investigating his son's business ties. About four in 10 said Biden probably did exert this pressure while nearly the same share said he probably did not.

"Trump may be facing backlash for this call but the irony is now that its contents are out there, it may actually help with his objective," Murray said. "And that is to sow doubt about Biden among voters."

View | 12 Photos

President Trump’s pressure on Ukraine draws comparisons to Watergate