Public support for impeaching President Trump rose this week after Speaker Nancy Pelosi (D-Calif.) announced that the House would open a formal impeachment inquiry, according to polls from Morning Consult/Politico and NPR/PBS NewsHour/Marist.

Why it matters: The lack of public support for impeaching Trump has long been cited by Democratic leadership as the main reason not to open an inquiry. But the polls show a significant shift in public opinion this week as the Trump-Ukraine controversy has rapidly unfolded, with Pelosi's announcement on Tuesday, the release of a summary of Trump's phone call with the Ukrainian president on Wednesday, and the declassification of the whistleblower complaint on Thursday.

By the numbers: The Morning Consult/Politico poll was conducted Sept. 24–26 and surveyed 1,640 registered voters with a 2% margin of error. The latest numbers show:

43% support impeachment proceedings against Trump, up 7 points from a poll on Sept. 20–22.

Opposition to impeachment dropped to 43%, falling 6 points.

Republican support for impeachment rose to 10%, up from 5% last weekend.

Independent support rose to 39%, up from 33%.

The NPR/PBS NewsHour/Marist Poll surveyed 864 adults on Sep. 25 with a 4.6% margin of error.

49% support impeachment, up from 39% in April.

46% oppose impeachment, down from 53% in April.

Between the lines: "The Ukraine story, and subsequent calls for his impeachment, have not changed Trump’s already-low approval rating. Forty-one percent of voters approve of Trump and 56 percent disapprove, roughly unchanged since the Sept. 20-22 poll," per Morning Consult.

Go deeper: The impeachment whip list