Throughout more than two months of the Democrats’ House impeachment inquiry, two critical questions have loomed: How will the American public react to what it uncovers? And will it help or hurt President Trump’s chances at reelection in 2020?

So far, four dozen national and state polls have been conducted since the inquiry was announced, and together they offer some clear answers.

After an initial rise, support stayed divided on impeaching and removing Trump.

Impeaching Trump was clearly unpopular this summer, standing at 39 percent supporting and 48 opposing in a Washington Post average of nationally representative polls from June through late September. But later in September — after House Speaker Nancy Pelosi (D-Calif.) announced the impeachment inquiry following a CIA whistleblower complaint about Trump’s request to the Ukrainian president to investigate former vice president Joe Biden and his son — support jumped to an even split at 46 percent in support and opposition.

Since that initial jump, however, support for impeachment has been stable. The Post’s average of nationally representative polls conducted since the start of the House’s public hearings on Nov. 13 finds 47 percent of Americans support impeaching and removing Trump, while 43 percent are opposed. That level of support is little different from the 47 percent support in the two weeks before hearings began and 48 percent support earlier in October.

Independents also are divided on impeachment.

Political independents have been a key group to follow in impeachment polls, since several surveys this summer showed independents opposed to impeaching Trump by a margin of more than 20 percentage points, the clearest signal of political risk to Democrats if they launched hearings.

National polls since the start of public hearings show independents are now divided: 42 percent in support and 44 percent opposed.

Democrats and Republicans are mirror opposites on the issue, with an average of 86 percent of Democrats supporting impeachment, compared with 9 percent of Republicans. Democrats have grown more united in their support for impeachment since before the inquiry began, when polls showed roughly two-thirds supported impeachment. Among Republicans, an average of 87 percent are opposed, while 8 percent of Democrats say the same.

In key general election states, fewer voters support impeachment.

Battleground state polls show a more negative reaction to the impeachment inquiry, signaling more risk to Democrats and potential benefit for Trump. An average of 44 percent supported impeachment, with 51 percent opposed, averaging across a dozen October and November polls in Arizona, Florida, Michigan, Pennsylvania, Nevada, New Hampshire, North Carolina and Wisconsin. That’s a flip from an average of national polls that finds support for impeachment narrowly edging opposition, 47 percent to 43 percent.

The depressed support for impeachment in key states was first signaled by a series of New York Times-Siena College polls conducted in mid-October, which found between 51 and 53 percent opposing impeachment in Arizona, Florida, Michigan, North Carolina, Pennsylvania and Wisconsin.

But several other polls also have found that support for impeachment in key 2020 states lags the country overall. At the most negative, a mid-November Marquette University Law School poll in Wisconsin found 40 percent of registered voters support impeaching and removing Trump, while 53 percent are opposed. Fox News polls in North Carolina and Nevada showed opposition to impeachment outpacing support by eight and seven points, respectively. The best results in key states have shown voters divided over impeachment, such as a Muhlenberg College poll of Pennsylvania voters.

Trump’s approval rating has hardly budged.

Overall job approval ratings are the essential baseline measure of a president’s political support, and Trump’s trendline in job approval is the clearest sign of whether his popularity has increased or decreased amid the impeachment inquiry. And it has barely moved over the past few months in national polling, including the period in which impeachment support increased in late September.

In Gallup polling from mid-September to mid-November, Trump’s approval has tiptoed between 39 percent and 43 percent approving. In Quinnipiac University polls, the story is no different: Between 38 percent and 41 percent of registered voters approved of Trump from late September to late November.

The stability of Trump’s approval ratings affirms just how locked-in Americans are in their views toward Trump, even as some independents and Democrats changed their opinion on whether Congress should impeach and remove him from office. The lack of movement in this essential measure of Trump’s political standing also indicates that while most Americans think Trump did something wrong in his dealings with Ukraine, news and congressional testimony about this issue have not shifted how people feel about the president.