Trump hasn't gotten a boost from Mueller -- and that's bad news for his re-election chances

President Donald Trump has not gotten the bounce he'd hoped for after special counsel Robert Mueller's investigation concluded without finding evidence of collusion.

The full report has not been released yet, and Attorney General William Barr has walked back his initial summary that some on Mueller's team are grumbling about, but even that guardedly positive news has failed to boost Trump's approval rating, reported NBC News.

That spells bad news for the president's chances for re-election.

A week after Mueller turned in his report to the Department of Justice, Trump's average approval rating has climbed just one-tenth of a percentage point, from 43.1 percent to 43.2 percent.

"Maybe when voters learn more, the numbers will move, in one direction or the other," said NBC News political correspondent Steve Kornacki.

"Maybe this is just the latest and loudest example of what we've seen over and over again during this presidency: A gigantic news development, followed by suggestions that a critical turning point in his public standing may be at hand, followed by ... well, pretty much nothing."

Trump has repeatedly dragged himself into one controversy after another, and even when his approval takes a hit, the damage usually doesn't last very long.

Even in summer 2017, when Republicans' deeply unpopular efforts to repeal Obamacare failed and Trump was rebuked by his own party for his response to the Charlottesville violence, the president's approval rating dropped to 37.4 percent -- but climbed back up in September to 40 percent, where it had been before the health care vote.

That pattern is both good and bad news for the president, because it shows most Americans are set in their opinions of him and are unlikely to change their minds no matter what happens.

Trump's approval peaked at 46 percent two weeks after his January 2017 inauguration, and he hasn't been above 45 percent since the following month, but he's never fallen below 37.1 percent, where he found himself after backing accused sex predator Roy Moore's failed Senate campaign in Alabama.

By contrast, every one of his modern predecessors has hit 60 percent approval at some point in his first term.

Kornacki found the same pattern played out during Trump's 2016 campaign, which he narrowly won despite large majorities of voters personally disliking him and doubting his temperament and qualifications for the job.

"Trump wouldn't be president unless at least some people who held all of these negative views of him voted for him anyway," Kornacki said.

To win re-election in 2020, Trump will need an opponent as unpopular as Hillary Clinton was in November 2016, when 54 percent of voters held an unfavorable opinion of her.