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

sarahf (Sarah Frostenson, politics editor): From the launch of his campaign to stump speeches on the trail, former Vice President Joe Biden is running on the idea that President Trump and his administration are an aberration. “This is not the Republican Party,” Biden recently told a crowd in Iowa. But some pundits, party operatives and other 2020 candidates think Biden’s stance is shortsighted and argue that Trump’s presidency is a symptom of a much bigger problem in the GOP.

So how much of an aberration is Trump? He has challenged norms and democratic values while in office, but Republicans have largely declined to break rank. Does this mean that Trump’s candidacy was just a reflection of the direction the party was already headed in?

natesilver (Nate Silver, editor in chief): Can you draw a through-line between Trump and the Republicans that came before him? Sure, yeah. I’m not sure it’s a particularly linear through-line, though.

Something can be in line with a trend but still be an outlier. Home runs are way up in baseball this year, but if someone winds up finishing the season with 83 home runs, that’s still an outlier. Climate change makes heat extremes much more likely, but if it’s 105 degrees in Boston in May, that’s still an outlier.

matt.grossmann (Matt Grossmann, political science professor at Michigan State University and FiveThirtyEight contributor): And the tendency for Republicans to get behind their president is actually one area of continuity. Republicans trust government consistently more under Republican presidents, often dramatically reversing course after a Democratic president.

julia_azari (Julia Azari, political science professor at Marquette University and FiveThirtyEight contributor): But at what point does it make sense to characterize something as an outlier? For example, people often point to the “Access Hollywood” tape or Trump’s remarks about the appearance of women, or his statements about immigrants as instances of norm violation. If you look at American history, racism and sexism aren’t unfamiliar themes, but it is unusual, especially in the modern era, for them to be so front and center.

nrakich (Nathaniel Rakich, elections analyst): Some Republican politicians were proto-Trumps. Think former Maine Gov. Paul LePage or Iowa Rep. Steve King. The rise of the tea party foregrounded a lot of Republicans who were saying outrageous things. And I don’t know if we want to count dog whistles, like the Willie Horton ad.

julia_azari: I would count those dog whistles and point out that Democrats were not immune to the temptations of making these kinds of appeals in that era either.

natesilver: Well, you can’t really characterize it as an outlier until you see where the next couple of data points line up, Julia. Which is why my basic meta-argument is that people are way too confident about this question, in either direction.

But that’s why I like the baseball or climate change analogy. Boston might be many times more likely to have a 105-degree day now than it was 50 years ago. That doesn’t mean it’s the new normal, however.

julia_azari: Of course we can’t know if Trump is the new normal yet. But I am not satisfied with this answer. I think we can and should have some sort of metric for whether his presidency is truly out of step with trends or historical patterns.

perry (Perry Bacon Jr., senior writer):

In New Hampshire, Joe Biden predicts that once President Trump is out of office, Republicans will have “an epiphany” and work with Democrats toward consensus. — Sahil Kapur (@sahilkapur) May 14, 2019

So this is the core question to me.

Does Biden actually believe this? Or is he just saying it because swing voters might like it?

sarahf: Right. On the question of whether Trump is an aberration, a lot of what we’re asking, I think, is whether a “return to normalcy” is even possible. Within the Democratic Party, there is a perception that former President Barack Obama spent years trying to compromise with congressional Republicans and that those efforts often fell flat — Merrick Garland’s thwarted nomination to the Supreme Court is an example these folks point to. And so now it’s a question of whether Democratic voters actually think bipartisanship can still work. Biden is clearly running on a platform that he thinks it can.

julia_azari: The normalcy Biden describes was never a thing.

perry: Do you think Biden is being sincere? Biden’s comment was almost exactly what Obama said in 2012 about how his victory would break the fever of GOP opposition, and Obama was totally wrong, of course. I was shocked that Biden said something that seemed so obviously clueless, but it might fit with his electoral strategy.

natesilver: I think Biden is being sincere, for what it’s worth. He came up in an era of relatively high comity and bipartisanship in the Senate.

nrakich: And Biden is friends with many Republicans in the Senate, like Lindsey Graham. It makes sense that he thinks he can woo them to his side.

But also a President Biden would probably need to get buy-in from only a few Republican senators in order to pass his agenda and get this “bipartisanship” thing to work.

I don’t think even Biden thinks he will convince a majority of the GOP caucus to vote for his policies.

matt.grossmann: Biden was the primary Democrat involved in cutting three separate budget deals with Mitch McConnell under Obama (going in wildly different directions), so he may have little reason to believe it can’t still be done. Believe it or not, most new laws are still bipartisan, and majority parties are getting no better at enacting their agenda.

sarahf: The McConnell whisperer!

julia_azari: Ha. From a strategic perspective, maybe it makes sense. It could be that people in the primary electorate are thinking more “I would like to get something done, and maybe Biden can do it” than “fuck the other party.” I’m not sure how any of the other Democratic presidential candidates think they will get their big policy ideas through a GOP-controlled Senate.

nrakich: I do think Biden has the best chance of striking deals with a GOP Senate. It’s just that people are overestimating how big of a difference he would make. Biden might be able to convince three GOP senators to vote with him. A President Tulsi Gabbard might be able to convince zero.

natesilver: TuLsI GaBBaRd hAs BiPaRtIsAn FrIeNdS ToO, Rakich, such as former Illinois Rep. Aaron Schock.

nrakich: Ha. That’s actually true — lots of Republicans are outspoken about how much they like Gabbard, so maybe she was a bad example.

But FWIW, according to a March poll from Quinnipiac University, Democrats said 52 percent to 39 percent that they would prefer a candidate who mostly works with Republicans rather than one who mostly stands up to them.

julia_azari: I just wonder if people want compromise in practice as much as in theory — and how having a divisive Republican president like Trump may have changed that.

sarahf: So, Julia, you’re saying that there might be a larger appetite now for a more combative Democratic president who is less willing to compromise?

I buy that, and I think we’re seeing that reflected in the messaging of several candidates.

julia_azari: Yeah, I think that’s a possibility. There is still this idea about building a new national consensus (at least on the Left). People think that there will be an election like 1964 or 1980 (at least, the narrative of 1980 as a landslide — Reagan won only 50.7 percent of the popular vote) and that there will be a 55 percent to 60 percent majority for a general approach to governance. But I think that’s a steep climb no matter how many rallies in the heartland or Amtrak trips through Scranton one takes.

matt.grossmann: 100 percent agree.

natesilver: I do think we have to ask how Republicans would react to Trump being defeated, by Biden or someone else.

Let’s say it’s pretty bad, for instance. The GOP loses the popular vote by 6 points, and all the major swing states go to the Democrat. Republicans lose another 15 House seats. And Democrats eke out a 51-49 Senate majority.

It’s been a while since we’ve had a one-term president, and that president (George H.W. Bush) came after Reagan had held two terms, so Republicans couldn’t feel too upset. Trump being a one-termer would be different, more analogous to Jimmy Carter.

nrakich: I’m not sure they would react that much, Nate? I feel like McConnell is just doing his thing, Trump or no.

matt.grossmann: Republicans would act like they usually do — a big backlash against the new Democratic president.

sarahf: You don’t think it matters to Republicans who the Democratic candidate is because party trumps everything?

nrakich: Sarah, I think some Republicans would prefer Elizabeth Warren or Bernie Sanders because they’re easier to demonize (in the same way that some Democrats preferred having Trump as the GOP nominee in 2016), and some would prefer Biden because they think the country would be less ruined under a more moderate president.

natesilver: But if Trump loses, we’d be looking at the Republican nominee having lost the popular vote for the presidency in seven out of eight election cycles.

And all of this happening despite a pretty good economy.

I don’t know. I think the party might react a lot differently than in 2008 when John McCain losing was more or less inevitable.

nrakich: Maybe Republicans would come out with an autopsy report again, like they did after the 2012 election, for how they can return to relevance — and then ignore it again in 2024, like they did in 2016.

matt.grossmann: But isn’t a backlash against the new Democratic president the best way to deal with that?

julia_azari: In the past, it has mattered somewhat whether the defeat was expected, but otherwise, losing parties have reacted by building up institutions, thinking about innovation, etc. My research on election interpretation and what we have seen with 2016 and 2018 suggest to me that Republicans would try to put forth an election narrative to serve their ends. For example, after 2012, some conservative commentators on Twitter advanced this “it’s hard to compete with Santa Claus” narrative, suggesting that Democrats’ victories were because they had promised unrealistic benefits to voters, rather than that they had won based on the strength of the campaign or the ideas.

nrakich: I’m sure there would be hand-wringing, but I just don’t know if it will change Republican behavior.

McConnell will still try to make the new Democratic president impotent, and the party’s new presidential hopefuls — the Tom Cottons and Mike Pences and Nikki Haleys of the world — will still go to Iowa talking about how unfairly Trump was treated.

natesilver: I’m reallllly not sure about that, Rakich. I think a lot of Republicans would be happy to throw Trump under the bus.

nrakich: You don’t think GOP voters (as opposed to elites) would still be loyal to Trump?

And therefore that the path to the 2024 nomination for Republican hopefuls would be cozying up to him?

If Trump loses, he will certainly remain a major force in the party. He’ll keep tweeting stuff to his base, and he might even run again in 2024! The GOP might be stuck with Trump as long as he’s still alive.

natesilver: I think you’re forgetting how much presidents are treated as losers once they lose.

Hillary Clinton has become relatively unpopular among Democrats, for instance, even though there might be a lot of reasons to feel sympathetic toward her.

matt.grossmann: And would it be that hard for Pence or Haley to thread the needle? They can offer a very different style of leadership but still say they believe Trump protected America and brought about economic recovery.

julia_azari: Yeah. I think it’s possible you will see Trumpism without Trump. In my opinion, the party has moved in a Trump-y direction (although I know Matt disagrees somewhat at least on the direction).

natesilver: “Trumpism without Trump” reminds me of “Garfield minus Garfield”:

nrakich: If it’s a close election, how many Republicans will think Trump lost fair and square, though?

natesilver: Well, I’m stipulating that it won’t be a close election.

nrakich: That’s true.

natesilver: (Stipulating, not predicting, for the case of this hypothetical.)

julia_azari: Even if it’s not, I think there will be narrative delegitimizing it.

matt.grossmann: Did we ever answer the question of whether calling Trump an aberration was a good strategy for Biden? It’s very similar to what Clinton and Obama said in 2016, but it may have been an ineffective strategy then; some Democratic-leaning voters decided it meant that Trump was less conservative than the Republican Party.

julia_azari: I’ve been thinking of the question as: “Will reaching out to anti-Trump Republicans in the electorate in this way convince them to vote for the Democratic candidate?”

But as Rakich said earlier, I think the conventional wisdom might overestimate the difference between having Biden in this position relative to any of the other candidates.

natesilver: Liberals on Twitter don’t seem to like Biden’s strategy, which is a strong sign that it’s a good strategy.

I think his comments about Republicans magically deciding to compromise were dumb, but overall the “Trump is an aberration” message is liable to be fairly well-received.

After all, Democrats spend a whole ton of time talking about how Trump is historically, unprecedentedly terrible and must be curbed, impeached, etc.

julia_azari: But Democratic primary voters might see it as a signal of less animosity toward Republicans, and my rather depressing read of a rather depressing political science literature suggests that may not be all that strategic.

natesilver: I think a lot of Biden’s messages are things that will do “just fine” with primary voters but are fairly good general election messages.

matt.grossmann: “I will be able to reach out to disaffected Obama-Trump supporters” is a good argument. “We have to get things done and I’m the one to do it” is a good argument. “I will get us past this horrible era” is even a good argument. But saying positive things about Republicans might not be necessary or even helpful.

nrakich: Remember that Biden has paired his “This is not the Republican Party” with a healthy dose of “Trump is a terrible human being and the worst thing to ever happen to America and someone who should be punched in the mouth,” which probably will appeal to primary voters.

natesilver: Also, keep in mind that Biden specifically rests his case on electability.

So if, hypothetically, independents like him because he seems more reasonable and that helps to prop him up in the polls, that could make primary voters more likely to stay with him.

julia_azari: Put that way, it comes down to whether Democratic primary voters hate Trump or Republicans more.

nrakich: (I think the answer is Trump.)

natesilver: Democratic primary voters hate Trump more than the Republican Party, right?

matt.grossmann: They do, but they dislike both.

natesilver: Or maybe it’s pretty close, actually. Only 10 percent of Democrats have a favorable view of the GOP.

nrakich: So maybe they don’t think of Trump as an aberration. Maybe they don’t overthink it. Maybe they just think the Republican Party is whatever it is in the moment.

natesilver: The fact that George W. Bush’s image has been rehabilitated quite a bit is interesting. And maybe suggests that Biden is right (strategy-wise) to treat Trump as an aberration. Bush left office with a very, very low approval rating, and now a lot of people feel nostalgic for him.

nrakich: Yeah, 61 percent of Americans said they viewed Bush favorably in this 2018 poll, including 54 percent of Democrats.

matt.grossmann: Trump was perceived differently than the Republican Party in early 2016, which is often what happens in a presidential contest. Opinions of Bush became less aligned with opinions of Republicans once Trump came along. But I don’t think it will be an issue in the same way this time around: Trump is now a known quantity and opinions won’t likely change until Republicans have another nominee.