Sen. John McCain, R-Ariz., expressed his party's uncertainty about President Trump running for office again in 2020, according to a report Saturday.

"They see weakness in this president," McCain told the New York Times. "Look, it's not a nice business we're in."

The report takes into consideration interviews from over 75 Republicans from diverse levels of the party. It notes donors and strategists as being more hesitant to stand by a Trump 2020 run, and points out a break from tradition as possible candidates that in prior years may have respectfully laid low this earlier on in the presidency, have been showing face at notable donor-filled Republican events.

McCain has been an outspoken critic of President Trump and went against the president's wishes last week when he helped defeat the Republican leadership's latest effort to dismantle Obamacare by voting "no" on the "skinny repeal" of the Affordable Care Act.

Trump and McCain have repeatedly butt heads since the beginning of Trump's 2016 presidential campaign when Trump quipped that he preferred people "who weren't captured," referencing McCain's time spent as a prisoner of war.