Welcome to FiveThirtyEight’s weekly politics chat. The transcript below has been lightly edited.

micah (Micah Cohen, politics editor): Greetings, all. I hope you got some sleep last night after the elections extravaganza!

natesilver (Nate Silver, editor in chief): It was such an exciting night that I couldn’t sleep. The most exciting election night of the month so far, I think.

micah: 😑

For us all to debate today: What role will the prospect of impeaching President Trump play in the 2018 midterms? Namely, can Republicans employ the threat that “Democrats will impeach Trump if they win the House/Senate” as a way to spur base turnout? Or, to take it from the Democrats’ POV, do they need to avoid impeachment talk? (Which they seem to have largely done so far.)

Perry, want to set the stage a bit? Have you seen much impeachment talk from either party so far?

perry (Perry Bacon Jr., senior writer): On the Democratic side, House Minority Leader Nancy Pelosi has told Democrats to stop talking impeachment, and they largely have. I wrote in March that I expected impeachment to become a big issue dividing candidates in Democratic House primaries. I was wrong. Some House Democrats did push an impeachment resolution, but it was quickly tabled, with just 66 votes in favor of bringing it up for debate.

On the GOP side, Trump is now talking about impeachment on the stump. He is bringing it into the 2018 debate, to rally GOP base, I presume. And parts of the conservative movement and media generally have started to make an issue of it.

micah: OK, so do you all think that’ll work?

And if so, how big of an effect could it have?

natesilver: There’s potentially a difference between “Republicans get to play defense/counterstrike on impeachment” and “Republicans invoke impeachment as a wedge issue when Democrats aren’t bringing it up much.”

The former I think could be effective — the latter, I don’t know.

micah: Wait, explain that difference a bit more?

You mean reality matters? (Whether Democrats are actually bringing up impeachment themselves?)

natesilver: Sure.

Is that a radical position?

Trump can say whatever he wants to the base-iest parts of his base, but they already have lots of things to get riled up about anyway.

For everyone else, I think it still helps to have some grounding in reality.

micah: Hmmmm …

perry: In, say, 1998, Democrats were able to make the case that the GOP was set on impeachment for political reasons. And that, I think, helped the Democrats.

In 2006 and 2014, the party in power pointed to fledgling impeachment efforts from the opposite party, and no one really took those seriously. Obviously, the details in those cases were much different than the current situation.

But I think the broader point from Nate is correct: If Pelosi were the leading figure in the Russia investigation or at least talking about it a lot, that would be a much different situation than what we have now, in part because the media would be covering Pelosi much differently (and more) if she were talking about impeachment a lot.

micah: So is the real question is whether impeachment can be used to affect the votes of independents and moderates?

natesilver: No, I don’t think that’s what I’m saying.

My point is just: Let’s not be too reductive here and assume that the reality doesn’t matter at all. If Democrats are campaigning on impeachment hearings in swing states, that’s much different than if a stray Democrat mentions impeachment once in a blue moon.

perry: I’m not sure I would dismiss impeachment having an effect on Republican turnout, though.

I just don’t know how hard the party will push that issue. Trump has mentioned it in a few speeches, but I haven’t heard the broader party or lots of candidates argue to voters, “Vote for House Republicans or the Democrats will definitely impeach Trump.” That would be an important message.

The Democrats who are talking about impeachment right now are very much not in swing districts, which is why this is a complicated subject.

micah: Should swing-state Democrats — or Democrats at large — just avoid it, then? Here’s friend-of-the-site Matthew Yglesias arguing “no”:

“But their preferred strategy of evading the issue has some obvious shortcomings. Their base wants impeachment, Republicans want to talk about impeachment, the media likes impeachment stories, and Trump’s conduct and unfitness for office are obviously the central issues in American politics and can’t just be swept under the rug. Democrats need to confront this topic by laying out a specific agenda to confront Trump and check his abuses of power, while also being clear that they are not going to let the congressional docket be dominated by a completely futile drive for impeachment.”

natesilver: Again, I go back to the fact that Trump is quite unpopular — getting slightly more popular, but still very unpopular — his net approval ratings are still roughly 10 percentage points underwater.

But when pollsters ask impeachment-related questions, the reverse is true — impeachment is usually 10 points underwater or thereabouts, depending on the poll.

micah: OK, here’s that polling:

In April, Monmouth University asked, “Do you think President Trump should be impeached and compelled to leave the presidency, or not?” and 39 percent said “should” vs. 56 percent who said “not.”

A Quinnipiac poll in April found 38 percent of people think Trump should be impeached and removed; 55 percent do not.

A new CBS News poll found that 30 percent of people would be more likely to vote for a Congressional candidate who supports impeachment; 40 percent said less likely. (Twenty-nine percent were unsure or didn’t answer.)

But there’s obviously a big partisan split; here’s the party breakdown from a Marist/NPR poll:

perry: Of course swing-state Democrats should avoid talk of impeachment. As that NPR poll shows, independents don’t support it. I’m sure people who voted for Trump but might consider voting for a Democratic congressional candidate in 2018 also don’t support impeachment.

I think the question for other Democrats, particularly those in blue areas, is different, They might think there is cause for impeachment now and, more likely, that there might be cause for impeachment (or at least hearings) by the time we are done learning whatever special counsel Robert Mueller has found. Take the Michael Cohen news from Tuesday; I think it’s really hard, right now, to rule out some kind of collusion with Russia, and I assume a lot of Democrats (and maybe some non-Democrats) would find that very troubling.

Matt’s other point — “completely futile drive for impeachment” — is that House Democrats shouldn’t vote to impeach Trump unless they think they can win a vote for removal (which is held in the Senate). That makes a lot of sense to me. But I assume some of the House members, like Al Green of Texas, who are pushing impeachment resolutions right now don’t necessarily care how Sen. Susan Collins would vote in a Senate trial.

micah: I think you all may be underrating the extent to which Democratic base voters want impeachment (see that NPR poll).

I guess my point is that I think Yglesias is right that Democrats need to say something about responding to Trump’s abuses.

natesilver: You know who I’m the least concerned about if I’m Nancy Pelosi? The Democratic base. Because they’re really excited about lots of issues ranging from Russia to health care to gun control. They’re gonna turn out in big numbers, I think that’s pretty certain. The question is what happens with independent voters and how much turnout the GOP base has.

perry: This gets us into questions about how tea party-ish the left wing of the Democratic Party is becoming. And I would suggest that that parallel doesn’t hold so far. Supporting impeachment is different from demanding a pro-impeachment stance from candidates in primaries. There is so far little evidence that pro-impeachment sentiment in the base is pushing Democrats in Washington or on the campaign trail to adopt such views.

micah: OK, those are both fairly convincing answers.

natesilver: That’s quite a concession coming from you, Micah.

micah: LOL

Let’s go back to this question from the GOP’s POV.

Here’s Yglesias again:

“Conservative pundits, meanwhile, are salivating over polling from Quinnipiac that shows impeachment to be a true wedge issue that commands overwhelming support from rank-and-file Democrats while the mass public expresses profound unease.”

Let’s posit a world in which rank-and-file Democratic candidates are not pushing impeachment. To what extent can Republicans still wield this as a wedge?

perry: Here’s what we know: The tax cuts are not popular and not motivating the base. I don’t see an issue coming down the pike that Trump can use to fire up Republicans and isolate Democrats. Maybe that’s immigration. Or a fight over Justice Anthony Kennedy’s replacement, if Kennedy retires. But to me, the impeachment position Trump has taken so far seems like a good one for motivating the voters his party needs in November: The Republican Party base is fairly pro-Trump and anti-impeachment, and swing voters tend to be anti-impeachment. Talking about impeachment plays into negative partisanship really well.

I’m not sure it’s a great strategy for swing voters, since it highlights that Trump is so controversial that maybe he should be impeached. But I think it might be good for the base.

In other words, I think Trump is making the right call politically to invoke this issue.

natesilver: I worry that this conversation has become too divorced from the things that would lead to Trump being impeached, e.g. the Russia investigation.

If Mueller comes back with an obstruction finding before the midterms, that obviously ups the ante a ****LOT*****.

micah: Wait, Nate … that’s not a very bold claim.

If the case for impeachment gets much better, of course that would change the politics of this.

On the flip side, if Mueller comes back with nothing tomorrow, it goes away.

natesilver: I’m just saying the impeachment question isn’t really on the table right now. And sure, Trump can pretend it is, but he can pretend a lot of things.

By the way, I wouldn’t assume that Mueller will come back with much before the midterms — The Wall Street Journal reported that he’d like to avoid that timing.

micah: OK, but then that’s your answer: You don’t think Trump pretending impeachment is on the table is an effective strategy.

perry: Well, I was trying to get at this earlier. Yglesias was saying that the case for impeachment will never be strong, because impeachment should only be on the table if removal is on the table, and removal can only be on the table right now if 17 Republicans back it, and that will never, ever happen.

micah: Perry, I get the argument that Republicans will never back removal, but I’m not so confident that’s true.

It all depends on what Mueller finds, I would think.

perry: I’m not sure that’s true.

micah: We saw this in past scandals: Partisans back their horse … until they don’t.

And even then, partisanship doesn’t go away completely.

Let’s take that 17 number: How far into the GOP caucus does that get you in terms of pro-Trumpiness?

According to our Trump Score tracker, the 17th least Trumpy GOP senator is Chuck Grassley; here they are, from voting against Trump’s position the most to least:

Rand Paul Mike Lee Susan M. Collins John McCain Lisa Murkowski Jeff Flake Bob Corker Ben Sasse Steve Daines Lindsey Graham Michael B. Enzi James E. Risch John Kennedy Patrick J. Toomey Mike Crapo James Lankford Chuck Grassley

That doesn’t seem like a huge stretch to me.

perry: Anyhow, I don’t think it will ever get to a vote like this in the first place.

natesilver: One probably ought to note that impeachment against Richard Nixon didn’t poll that well, until the bitter end.

This is a long argument, but I think the conventional wisdom tends to neglect the extent to which we don’t have a lot of relevant data on how Congress would behave depending on what Mueller comes back with, etc.

perry: But I liked Nate’s point, even though don’t agree with it, that Trump can’t make up an impeachment process that doesn’t really exist and fire up the base with it.

Is that what you were saying? Basically?

Like invoking the specter of impeachment must be related to a reality of impeachment.

natesilver: I’m saying he can make up a lot of stuff to fire up the base with, impeachment being one of those things.

micah: I don’t know what that means, Nate.

natesilver: For the issue to motivate the base above and beyond the usual litany of things, I think there has to be some meat there.

micah: You think its marginal value is low. Ah, OK.

natesilver: Yeah, sort of. I think you’re not thinking in terms of value-above-replacement-level, so to speak.

micah: OK, but — to wrap — then I go back to my point earlier: Isn’t the real question here then whether it can be used to sway non-base voters?

natesilver: Not exactly.

micah: GOP operatives are “salivating” over this data, presumably, because it shows independents and moderates against impeachment.

natesilver: I’m saying right now, impeachment is worth, say, 50 Motivation Points™ to the base. But anything that Trump focuses his time on is worth 50 Motivation Points, because he’s a skilled communicator in that way and he has lots of openings. If impeachment becomes a real thing — if Democrats actually start talking about it — maybe it’s worth 80 Motivation Points instead. Then it has some real value above a replacement-level grievance.

perry: Impeachment, to affect non-base voters, would have to be part of the news cycle. And it won’t be as long as Pelosi is downplaying it.

micah: You all agree!

I’m less convinced it has to be real to have an effect.

But we’ll have to agree to disagree.