Some rank-and-file congressional Democrats favor starting impeachment proceedings against President Trump. Even Democrats who don’t favor impeachment, such as House Speaker Nancy Pelosi, have suggested that Trump’s behavior could be impeachment-worthy, pointing to his administration’s refusal to comply with Congress’s requests for documents and testimony from key officials and the Mueller report’s references to potential obstruction of justice by the president. But Pelosi has downplayed the possibility of pursuing impeachment, hinting that such a move would hurt Democrats electorally.

Put simply, the impeachment of Bill Clinton hangs over everything — Republicans impeached Clinton in 1998, and voters rallied to his defense. Pelosi and other senior Democrats probably fear a similar backlash.

But are they right to?

In the short term, yes. Polls show that impeachment proceedings, at least at their start, would probably be opposed by a plurality of the public. The long term is more complicated, however. If House Democrats impeached Trump sometime in 2019 but he remained in office, would the process meaningfully decrease the party’s chances of retaining the House and winning the Senate or presidency in November 2020? That’s not so obvious. (We’re assuming for this article that a House vote to impeach Trump would be followed by an acquittal in the Senate, so the president would not be removed from office.)

Let’s unpack the electoral politics of impeachment in more detail, with a few precise questions.

Would impeachment hurt congressional Democrats in the near term?

Probably.

Since the release of the (redacted) Mueller report, some news and polling organizations have asked the public questions about impeachment. There is a clear pattern in the results:

Republicans overwhelmingly oppose impeachment (91 percent to 5 percent in a recent NPR/PBS NewsHour/Marist poll that asked whether impeachment hearings should be started in response to the Mueller report).

Independents oppose impeachment but by a narrower margin than Republicans do (51-40, according to the Marist poll).

Democrats largely support impeachment (70 percent, in the Marist survey), but there is still a sizable anti-impeachment bloc among Democrats (23 percent opposed).

So at least for now, impeachment doesn’t look like a great idea for Democrats politically — it divides the party, unifies Republicans and pushes independents toward the GOP.

But those who favor impeachment argue that these poll results should not be taken too seriously. “People don’t have preformed opinions about what merits impeachment the way they know their health care sucks or whatever,” wrote Brian Beutler, editor-in-chief of Crooked Media, the company that produces the popular liberal podcast “Pod Save America.” “Support for impeachment has dropped since the Mueller report … because Democratic leaders aggressively crapped all over the idea from the word ‘go.’ Having successfully eroded public support for impeachment, those same leaders can now point to the polling they shaped as a reason not to act.”

Is Beutler right? Maybe. In this era of deep partisan polarization, I would assume that support for impeachment among Democrats would increase if party elites — particularly people who are aligned with the party’s moderate voters like Joe Biden — all started pushing for it. Also, the process itself, which would probably include nationally televised hearings in which Mueller and others described the allegations against Trump in detail, could increase support for impeachment among the public. That’s what happened in the 1970s: Public support for the idea that Richard Nixon should be removed from office surged in 1973 and 1974 as Congress investigated the president and laid out the evidence against him.

But the polarized politics of today work in the other direction, too — it’s difficult to imagine Republican elected officials or GOP voters breaking with Trump as they (eventually) did with Nixon. By 1974, Nixon’s approval rating among Republican voters was in the mid-50s. Trump’s has been mostly in the upper 80s throughout his presidency despite a seemingly endless list of controversies that the media has cast as politically damaging.

In terms of public opinion, probably the best that Democrats can hope for is a 50-50 split on impeachment — basically, Clinton voters in favor and Trump voters opposed. But it’s entirely possible that impeachment remains a net political loser for Democrats.

Which leads us to another argument against impeachment, that Democrats should instead focus on issues where a clear majority of the public is on the party’s side. This is Pelosi’s strategy, pushing more popular proposals like defending the Affordable Care Act provision that bars insurance companies from denying coverage or charging higher prices for people with preexisting conditions, and making it easier for Americans to register to vote on Election Day.

So even if impeachment is basically a 50-50 issue and wouldn’t hurt Democrats’ standing all that much, you could argue that it’s a bad political move because Democrats could be focusing on issues where, say, 70 percent of Americans agree with them.

Would impeachment boost Trump’s job approval ratings in the near term?

Probably not.

Pelosi has suggested that Trump’s base would be extra energized by impeachment. I’m skeptical of this claim simply because Republicans are already strongly behind Trump. Trump’s job approval rating among Republicans is at 91 percent, according to Gallup. Could it increase by a couple of percentage points? Sure. But he has only so much upside left.

Could Trump become more popular among independents, who might view impeachment as an overreach by Democrats? Maybe. But I think the much safer prediction is that Trump’s poll numbers wouldn’t change much. Indeed, that’s been the norm during his presidency so far.

“Sentiments towards President Trump seem remarkably stable given the often tumultuous nature of his time in office,” Robert Griffin of the Democracy Fund Voter Study Group, a group of scholars who research the views of American voters, wrote in a recent analysis of the president’s public standing.

Would impeachment hurt Democrats electorally in November 2020?

Maybe in down-ballot races.

Midterms are usually won by the party that doesn’t control the presidency. It’s as close to a universal rule as politics has. But in November 1998, when Clinton was in the White House, Democrats gained a net of five House seats. Exit polls that year found that the public was wary of the GOP push to impeach Clinton, and Democrats at the time believed that anti-impeachment sentiment helped them.

Pelosi was in Congress in 1998, so she may be particularly inclined to see the potential for an impeachment backlash. And Pelosi has reason to be attuned to the potential dangers of pushing for impeachment — she is speaker in part because 31 Democratic candidates in 2018 won districts that Trump won in 2016. For those House members, deciding how to vote on impeachment would be really challenging — reject the president who was supported by most of your constituents or reject your party’s most intense supporters. Democrats running in gubernatorial and Senate races in states where they clearly need Trump voters to win (Montana, for example) might also be leery about supporting impeachment.

That said, we shouldn’t overstate the impeachment backlash from two decades ago. Even though the impeachment effort against Clinton was unpopular, Republicans kept control of the House and won back the presidency in 2000. And even though Clinton’s approval rating remained high, the Democrats’ presidential candidate in 2000, Al Gore, distanced himself from Clinton. Gore reportedly felt that the controversy around the president and his impeachment made voters wary of Clinton even if they said they approved of him.

If Trump were impeached, would that hurt the general election prospects of the Democratic candidate, especially if the nominee had supported impeachment? There are swing voters, and they matter. The question is what issues will be motivating them in 2020. Republicans will probably campaign against what they cast as Democratic extremism, both on policy (the Green New Deal and “Medicare for all,” for example) and politics (anti-Trump fervor).

I’m not sure impeachment would change that dynamic too much. Even if Democrats do not try to remove the president, Republicans can easily cast Democrats as extremely anti-Trump, because they are. Impeachment or not, 2020 is likely to be a referendum on Trump’s leadership and whether voters feel Democrats would govern the country better.

Would impeachment help Trump’s reelection prospects?

Maybe, but probably not.

Above, I dismissed the idea that Trump would get a short-term boost from impeachment. But what if he can spend a year saying the Democrats tried to remove him from office? Well, here’s the thing: Impeachment or not, Trump is likely to act as though Democrats tried to get rid of him. He has already cast the Mueller investigation as akin to a “coup.” The idea that Democrats are obsessed with taking Trump down will likely be in the president’s campaign commercials and echoed by Republicans in Congress and on Fox News no matter what Democrats do in the next 17 months.

Americans’ views on Trump’s presidency appear to be fairly set — the safest bet is that impeachment doesn’t change them too much.

To emphasize the obvious: The electoral impact of impeachment is really difficult to predict. It’s not clear that an impeachment push would hurt Democrats electorally (or help them).

So that leaves Democrats with an underlying question: How strongly do they believe in the case for impeaching Trump, electoral considerations aside? As long as Republicans remain behind Trump, impeachment would be a symbolic action to some extent. But it’s still a powerful and important symbolic act.