In a Quinnipiac University poll last month, six in 10 Americans said they believed Trump had an affair with Daniels and knew about the hush money. But seven in 10 said it wasn't important.
Quinnipiac has measured views of Trump's honesty since his term began. The proportion of Americans who consider him dishonest has never fallen below 54 percent.
Of two big targets he frequently accuses of lying, ex-FBI Director James Comey and the news media, Quinnipiac found that majorities trust them more than the president. Fully 55 percent overall – 16 percent of Republicans, 53 percent of independents, and 92 percent of Democrats – said Trump lacks "a sense of decency."
Those assessments have damaged the president and fellow Republicans. Fewer Americans approve his job performance than that of any recent predecessor at the same point, even with the economy humming and international affairs comparatively calm.
But views of Trump's character have largely lost their ability to change his current standing. As unflattering information keeps accumulating, the share of Americans approving of him has ticked up from slightly below, to slightly above, 40 percent.
After 16 months, Americans have grown accustomed to Trump in the White House. The longer he serves without economic downturn or war, the more inured they become to his behavior.
"People have concluded that he's a liar," explained Mark Mellman, a leading Democratic pollster. "He lies every day. People know it."
At the same time, "The world hasn't come to an end," Mellman added. "The world's looking a little better. There's some good news out there."
The Labor Department announced today that the unemployment rate has fallen below 4 percent for the first time since the end of the 1990s boom. Peace talks have broken out on the Korean peninsula. Trump plans a summit with North Korean leader Kim Jong Un.
History shows that any president's standing represents a crucial determinant of his party's fate in midterm elections. Trump's weak ratings mirror the significant Republican deficit in polls measuring preferences for control of Congress this fall, giving Democrats a chance to recapture the House and Senate.
As it stands now, said Democratic pollster Margie Omero, deepening Trump scandals harden existing opposition to the president and "make it incredibly hard for Republicans to turn their fortunes around." A major new shift in Democrats' favor would require a profound jolt from concrete developments – such as an indictment by special counsel Robert Mueller alleging that the Trump campaign had conspired with Russia on the 2016 election.
Views on the economy pose a larger and more immediate variable. Passage of tax cuts last December showed a GOP-controlled Washington could get something done.
But relatively few voters tell pollsters they believe they'll benefit. So far, the tax cuts have produced little political or economic dividend. Potential fallout from the trade wars Trump keeps threatening has alarmed Republican lawmakers from agriculture and auto-producing states.
More critically for Republicans, the small minority of voters most susceptible to changing their minds still haven't arrived at a verdict about Trump's effect on their lives. One in five of his 2016 voters viewed him unfavorably even as they elected him.
"They knew the foibles," said David Winston, a pollster for GOP leaders in Congress. "What they were trying to do was shake up the system. They have yet to reach a conclusion on: is it working, or not?"