President Donald J. Trump debates with House Minority Leader Nancy Pelosi, D-Calif., and Senate Minority Leader Chuck Schumer, D-N.Y., as Vice President Mike Pence listens during a meeting in the Oval Office of White House on Tuesday, Dec. 11, 2018 in Washington, DC.

President Donald Trump retains strong support from fellow Republicans, but Americans overall express growing unease about his potential involvement in criminal wrongdoing, according to the latest NBC News/Wall Street Journal poll.

A robust 62 percent majority say Trump has not been honest about the investigation into Russian interference in the 2016 presidential campaign, up from 56 percent in August. A 46 percent plurality says guilty pleas by Trump associates suggest wrongdoing by the president as well, up from 40 percent in August and 36 percent a year ago. Half the public say the investigation by Special Counsel Robert Mueller has given them more doubts about Trump's presidency.

The telephone survey of 900 adults was conducted Dec. 9-12, amid accelerating developments in investigations by Mueller and other federal prosecutors that have ensnared the president's personal lawyer, campaign chairman and first national security advisor. It carries a margin for error of 3.27 percentage points.

"The dam has not burst on Donald Trump," says Peter Hart, the Democratic pollster who conducted the NBC/WSJ survey with Republican counterpart Bill McInturff. "But this survey underscores all the structural cracks in the dam."

The survey comes one month after a mid-term Congressional election that empowered Democrats intent on scrutinizing the president's conduct. It shows that Americans support that scrutiny, with 55 percent embracing the prospect of House investigations of the administration compared to 43 percent who don't.

Moreover, the concerns the poll highlights about Trump's integrity suggest that the kinds of policy adjustments his predecessors have made after mid-term defeats wouldn't make much difference for him.

"This is not a vote of no confidence," Hart said. "it's worse – a vote of no trust."

The survey points toward discontent with both political parties. Democrats remain barely above-water in public esteem, with 39 percent expressing favorable views and 37 percent unfavorable.

But Republicans are underwater, with 32 percent favorable and 42 percent unfavorable. A 48 percent plurality of Americans want Democrats to take the lead in setting policy for the country, compared to 21 percent who say Republicans and 19 percent President Trump.