OSHKOSH, Wis. -- As President Trump marks five months in office Tuesday, he has hit a new low in a CBS News poll.

Only 36 percent of Americans told us they approve of the job he's doing. Mr. Trump is even losing support among Republicans.

At Two Brothers Restaurant in Oshkosh, Wisconsin, Trump supporters like Ken Schoenike are getting impatient -- but not with the president.

"Leave him alone. Let him do what he wants to do. The media is hounding on him constantly. I mean, really?" said Schoenike.

This group of retirees backs Mr. Trump on almost every move he makes, but with one exception, according to Adolf Hendricks.

"I think I would like to see him a little more presidential, perhaps, a little more dignified," he told CBS News.

Les Talo says enough with the tweets.

"It just gives the Democrats fodder for their daily attacks on him," Talo said.

A group of retirees speak with CBS News' Dean Reynolds about President Trump's performance. CBS News

Warren Thomson dismisses the big issue consuming Washington: the Russian investigation. CBS News asked the group if they ever talk about the Russia probe and if it bothers anybody.

"This whole thing -- as far as I'm concerned -- is a conspiracy… it's a total distraction," one man said.

They are among the 72 percent of Republicans who remain in Mr. Trump's corner, according to a new CBS News poll. But that number is down from 83 percent 52 days ago. And Mr. Trump's disapproval rate among Republicans is up seven points.

CBS News

Jennifer King, a church and school secretary, voted for Mr. Trump. We asked her what grade she would give Mr. Trump now.

"Probably a low C," she said.

"I still support him, but I would like to see some real results," she added.

Jennifer King CBS News

King wants tax cuts and more help for veterans, but believes Mr. Trump is too easily sidetracked.

"He is too busy fighting the media. He's too busy fighting accusations," she said.

When asked what she thinks is the problem, she answered: "I personally think it's his mouth."

But whether committed or wavering, these Mr. Trump voters believe that he hasn't been treated fairly. Most are willing to give him at least two years on the job before they would reconsider their support.