Will Democrats get complacent if they win big in 2018?

[Zaybay]

Just winning the House would not be enough to make Democrats complacent.

It was for the Tea Party. They were so sure Obama would be a one-termer after 2010.

#Resistance seems to have that same kind of complex.

Problem is, The Deplorables will wake up just as Obama's base did and might be powerful enough to make 2020 another 2012.

They'll get complacent even if they lose big. See 2014 and 2016.

I don't know. They seem to hate Trump more than they liked Obama. Hate is a stronger motivator than satisfaction.

Because that's how 2012 went for The Tea Party huh. They hated Obama more than ever liking Bush...and yet Romney underperformed and they lost seats in both chambers of Congress.

The problem with that analogy is that the Tea Party is much smaller than the #Resistance. Obama won by a large margin in both elections, while Trump has only lost the PV by 2. Democrats will likely not get complacent, as its Trump they are truly after. After 2020, maybe, before, no.

[Zaybay]

The answer is no. The whole reason 2018 is becoming a massive wave is because of their opposition to Trump, and I doubt many Democrats will call it a day after winning big in 2020. There may be a case for 2022, but I cant be sure on the factors of such an election this far out.

Also:

Democrats narrowly capture the House in 2018, learn all the wrong things in the process, and then lose narrowly to Trump in 2020.

What do you think they'd learn, and what do you think they "should" learn?

They'll win the House by electing a lot of Josh Gottheimer clones in Romney-Clinton districts, then they'll nominate a Booker or Harris type in 2020 who will come up short in PA, MI, WI, etc.  

So far, only 8 candidates are similar Josh Gottheimer who are in lean D or tossup districts, 9 if you count Case. The rest are much closer to Sanders, Harris, Warren, Gillibrand, the left and center-left of the party, not the conservative side of it. In fact, your example would be Dems taking the right lesson from 2018.