President Donald Trump makes a statement at the White House following reports that U.S. forces attacked Islamic State leader Abu Bakr al-Baghdadi in northern Syria, in Washington, October 27, 2019.

About half of Americans now want Congress to impeach President Donald Trump and remove him from office, up slightly from a month ago, a new NBC News/Wall Street Journal poll shows.

In the survey, 49% back Trump's impeachment and removal while 46% oppose it. In the NBC/WSJ poll a month ago, a 49% plurality opposed impeachment and removal while 43% favored it.

Paradoxically, that increase represents a sharpening rather than blurring of partisan lines as the House impeachment inquiry accelerates. Support for Trump's impeachment and removal actually dropped to 6% from 11% among Republicans – a decline more than offset by rising support for impeachment among Democrats and, to a lesser degree, independents.

"It's a very locked-down electorate," said Peter Hart, the Democratic pollster who helps conduct the NBC/WSJ survey.

While support for impeachment rose, Trump's job approval level ticked up by two percentage points to 45%. Hart's GOP counterpart Bill McInturff called that a sign that, so far at least, the investigation of Trump's dealings with Ukraine has not shifted overall assessments of the president.

"We're not seeing a change at all in Trump's standing," McInturff said. The telephone poll of 900 American adults, conducted from Oct. 27-30, carries a margin for error of 3.27 percentage points.

Nor has the success of U.S. special forces in the death of ISIS founder Abu Bakr al-Baghdadi made a major dent in public opinion. While 40% of Americans said it made the U.S. more safe, the rest did not.

The poll showed that Baghdadi's death did not seize public attention as much as other top news events of recent years. And it was offset by Trump's announcement that he would withdraw U.S. troops from northern Syria, which 41% called the "wrong decision" and 35% said would make the U.S. less safe.