Just over 3 percent of those who backed Donald Trump for president now regret their vote, according to a Mood of the Nation poll from Penn State's McCourtney Institute of Democracy.

"Of the 339 poll participants who originally voted for Trump, only 12 (3½ percent) said they would do something different," Michael Berkman, director of the institute and Eric Plutzer, who directed the poll, wrote in The Washington Post.

Here are some of the reasons given by those surveyed, according to Berkman and Plutzer:

"I don't like his decisions so far."

"Trump's actions since the inauguration."

"… Trump cannot get out of his own way. He won't stop running his mouth and has no humility."

But just one in four of those who expressed second-thoughts, now say they would have supported Trump's opponent, Hillary Clinton, the two political science professors said in the Post.

"Of the 327 Trump voters who would vote for him again, only 42 (or 13 percent) asked him to start behaving more presidential," Berman and Plutzer wrote. "Typical was a 51-year-old woman from Virginia who said she would tell the president, 'Continue with your agenda but stop tweeting.'"

Most of the Trump voters sampled asked the president to "stay strong," "keep it up," or "hang in there."

"For Trump's supporters, any news reports that his first weeks as president have been rocky, unpresidential or worse have hardly mattered," Berkman and Plutzer wrote. "There is virtually no regret.

"While his governance has galvanized opposition groups and his overall approval level remains low by historical standards, his electoral base is not only intact but enthusiastic and energized, providing Trump with a significant base of power."