Why did it take until 2018 to sink most Clinton seat Republicans?

[ElectionsGuy]

This is something I'm generally still curious about. In 2016, most Republican incumbents in suburban districts that trended Democratic hung on, and way outperformed Trump. This is seen in Senate races too (Ron Johnson in WOW, Toomey in SEPA, Kirk in Collars) too. In 2018, they mostly did worse or performed on par with what Trump did.

My premature explanation would be that in 2016, it was easier to separate traditional Republicans from Trump, as you could vote Republican down ballot but just not for president. Also, many congressmen and senators distanced themselves from Trump and didn't say whether they'd vote for him in 2016. In 2018, Trump wasn't on the ballot but almost all congressional races were nationalized and tied to what people thought of Trump. Republicans at this point were forced to back Trump. Another explanation could be the Republican party is now 'Trumpified' with Trump being president in a way it wasn't yet in 2016, in that almost all Republicans now perform like Trump at the congressional level. But this is essentially just a result of what I said in the sentence before.

Any other thoughts? While this could justify, I'm curious if there were any other factors at play.

[Roll Roons]

A lot of those suburban districts were traditionally Republican (IL-06, KS-03, NJ-07, TX-07, TX-32, VA-10, all of the Southern California ones), and had voted for Romney. Hillary won them because Trump was such a bad fit for suburbanites - Kasich, Jeb! or Rubio would have likely kept them in the GOP column.

[OSR stands with Israel]

A lot of those suburban districts were traditionally Republican (IL-06, KS-03, NJ-07, TX-07, TX-32, VA-10, all of the Southern California ones), and had voted for Romney. Hillary won them because Trump was such a bad fit for suburbanites - Kasich, Jeb! or Rubio would have likely kept them in the GOP column.

[RINO Tom]

It's pretty simple, if you are dissatisfied with Trump enough and voting in 2018, you have literally one way to show it: vote Democrat.

[Zaybay]

There are two parts to this really.

One is the rather obvious reason. These districts voted for Clinton and were repelled by Trump and his policies. The Blue Wave combined with presidential patterns seeping into congressional races were a big reason many of these Reps lost.

But a second big reason is the changing demographics of these seats. Increasing urbanization in seats like KS-03, Dem spillage in seats like CO-06, and rapidly changing demographics like in GA-06/GA-07. The underlining trends made these seats too marginal to be held, and in the end the dam broke for many of them. You can partially blame the GOP for this collapse, as many states were maximized for GOP efficiency, which meant having a lot of districts but having them be rather marginal. TX is a good example of this, along with NJ(though that was done by a commission).

Basically, a dislike for the Trump GOP and changing demographics.

[Gracile]

1) Many of those Clinton seats that Dems picked up had not voted for a Democratic presidential candidate in ages until Clinton won in 2016 (CA-39, CA-45, CA-48, TX-07, TX-32). In others, Mitt Romney improved on McCain's margins from 2008 - leading to several Obama-Romney districts (CA-25, CA-49, IL-06, VA-10). The conventional wisdom before 2016 was not always "these suburban seats are going to shift heavily toward Democrats." If anything, Romney's relative overperformance at the time indicated a reversion back to their prior voting habits.

2) 2018 was the most favorable national environment for the Democratic party since Obama's 2008 victory. In 2010 and 2014, House Democrats were mainly playing defense against some pretty nasty headwinds directed at their president and party. There was little effort made toward ousting Republicans in vulnerable seats, and even then those vulnerable Republicans still benefited from being in the party out of the White House. We can see a similar effect today as there are now more Democrats in Trump seats than there are Republicans in Clinton seats.

3) Until recently, members of Congress could effectively run away from their national party. Representatives like Paulson, Coffman, and Curbelo were able to present themselves as moderates who veered away from the GOP or otherwise being good stewards to their communities. Trump's election has made overperformances for these Republicans much less frequent as the results of the 2018 House races mostly tracked 2016 presidential results in those districts. Many Republican representatives tried to present themselves as moderates in 2018 (not so much in terms of voting record, but rather an image of being moderate). However, those tactics proved ineffective as voters in many Clinton districts were unable to separate their "moderate" incumbent from the far-right national GOP.

[freepcrusher]

the same way it took until 2010 to sink a lot of McCain seat democrats

[Senator Incitatus]

I think there was a lot of Clinton-Republican voting because Clinton voters didn't expect Trump to win and felt comfortable voting for (e.g.) Leonard Lance and Pete Roskam as a check on her. When that reality went unrealized, it was time to put a check on Trump instead.

American politics has this weird schizophrenic obsession with checks-and-balances that is frankly awful.

[Tintrlvr]

I think there was a lot of Clinton-Republican voting because Clinton voters didn't expect Trump to win and felt comfortable voting for (e.g.) Leonard Lance and Pete Roskam as a check on her. When that reality went unrealized, it was time to put a check on Trump instead.

American politics has this weird schizophrenic obsession with checks-and-balances that is frankly awful.

I agree, I think that's exactly what happened. Swinging voters in Clinton-Republican districts assumed Clinton would win so they should vote Republican down-ballot. I don't think that's a totally crazy posture for a moderate voter who would genuinely prefer a compromise result to take, either, although I think relatively few voters are actually moderate on issues instead of holding non-moderate views on different issues in both directions.

[💥💥 brandon bro (he/him/his)]

Lots of good answers in here but I want to posit another theory -

I know "incumbency advantage" is mocked here but I think it's a pretty compelling explanation for why there are time-lags in districts shifting along with their demographics.

In the absence of other forces people will generally stick with inertia, even (especially) if that's a no-name backbench congressperson who takes generic party-line votes. Even when that person is at odds with shifting coalitions or demographics within their district they still generally can draw upon an established base of support. This is why candidates like Sherrod Brown and Jon Tester are still viable candidates. However, when they retire and are replaced by somebody new the change is stark and it's enough to encourage people to switch votes - D Senators in the Dakotas (obviously sans Heitkamp) and their R successors are great examples of this. Another great example is Northern Virginia districts that had been voting Democratic federally for almost a decade continuing to reelect Republicans for HoD/State Senate even up until 2015; those that retired were replaced with Democrats, but those that had been in office for years had a base to lean on to get reelected. If Collin Peterson retired in 2018 (or 2016) he would have easily been replaced by a Republican and we saw vacancies in MN-01 and MN-08 finally create openings for Republican candidates to capitalize on changes in those districts.

Part of what happened in 2018 was many of these Republicans retired anyway. Of course Trump's takeover of the GOP was enough of a force to actually get people to vote against their incumbents. But in a sense many of those Clinton-seat Republicans were running on borrowed time because of their incumbency and Trump was a big enough shock to the system to finally get them to pay the debt.

[morgieb]

You have to remember that none of these seats were Safe Democrat before 2016. It's more surprising that they went so soon, though in fairness a lot of that has to do with a wave happening after 2016 (whereas 02/06 were Republican midterms so those double digit Clinton/Bush seats weren't ripe to flip yet)

[Blair]

1.) Money- without looking at the stats I assume most of these seats didn’t have GOP incumbents being outspent 3-1, and also didn’t have the huge liberal ecosystem that grew in 2018. Pod Save America weren’t doing GOTV in 2016- they were sat on a sofa being snarky. There was a whole campaign movement flush with cash that targeted these seats.

2.) Record- it’s much easier to run against President Obama, and do f all in Congress, than it is to defend not just your own voting record, but also two years of republican sh**tshow level decisions. No doubt even if you voted against the tax cut/repeal, you’d still have voters wanting your head because your party did it. 

[IceSpear]

They thought they were voting for a check on President Clinton, and what they got was a rubber stamp for President Trump.

[Kevin]

I think there was a lot of Clinton-Republican voting because Clinton voters didn't expect Trump to win and felt comfortable voting for (e.g.) Leonard Lance and Pete Roskam as a check on her. When that reality went unrealized, it was time to put a check on Trump instead.

American politics has this weird schizophrenic obsession with checks-and-balances that is frankly awful.

This...

I am from VA-10 and despite gradual Democratic trend of the district) many people in places like Ashburn and McLean voted to reelect Comstock as a hedge against an another President Clinton. It was not uncommon to simultaneously see Clinton and Comstock signs in people's yards.

Once Trump won that all went out the window and the GOP collapsed here in 17 and 18.

I imagine the same has occurred in Suburban New Jersey, Southern California, etc.