What does a new Democrat-dominated party system look like?

[Person Man]

So the coalition would be exactly what it looks like now

I'm talking about something sufficient to lock down the electoral college by New Deal Coalition margins. Something to end the polarization keeping the map stable and balanced, where the Democrats become a true majority party. As evidenced by Trump, a Republican can and will win in this environment given the right drop in turnout.

Democrats will never be able to win by New Deal-era margins as long as the two parties remain as ideologically sorted as they are today.  The Dem's massive wins in 1932-44 required the votes of conservative, Southern Democrats and agrarians.  

Right, and this is a thread about a hypothetical new party system in which that's possible.

Well then it's not possible unless Democrats are serious about courting Southern Evangelicals.  

Democrats wouldn't be able to get New Deal coalition margins again without making at least some inroads with white Southern Evangelicals, but there are definitely scenarios where they could become the definitive majority party on the national stage without them. Many white Evangelical political demands are already increasingly becoming out of alignment with much of the country.

If the Democrats play into the demands of Evangelicals then they lose another block of voters simple enough, what I think would be interesting is a party in the future where the Democrats and Republicans have both collapsed that is primarily composed of African American + White evangelical voters which would be practically unbeatable in the South, and it could make a play at many western and midwestern states.

Like an American Solidarity Party that dominates the south and perhaps the southern wheat and corn belts?

What about this map?
https://www.270towin.com/maps/npLzn

But back to the original Democrat-controlled system. I just think these things need to happen:

1) Finding a way to keep the party together and turning them out
2) Roe v. Wade being effectively overruled and being given the luxury of being flexible on abortion in a way that will turn out the base and not scare off swing voters. This is especially the case with Republicans now having to defend their policies. Maybe it will make
3) easier. Which is to find a way a to keep the R base from spamming the polls. 

[Person Man]

This is kind of building up/actually happening.  The problem for them was that the rustbelt flipped before the sunbelt did.  But I think they could maintain this coalition for a few cycles before new divisions in the electorate occur.  They could have a huge margin in the house with a lot of seats on the two coasts + Illinois.  Plus a small margin in the senate.  It would probably happen all at once. Basically like what happened in Virginia.  They could have a sustainable majority based on just urban/suburban states and districts the way Democrats do in Virginia without any real rural support at all.  Which means they could just push through their agenda (especially on social issues) without fracture. 

There's one problem with this theory: urban/suburban states have the Senate somewhat weighted against them. Given how many pro-filibuster Senate Democrats remain, they are not going to be able to push through their agenda without fracture for a long time.

Not who you were responding to but, given how many Senate Republicans said they were 'pro-filibuster' until the time came to actually put up or shut up, I'm not so quick to give "pro-filibuster Senate Democrats" the benefit of the doubt in what they're saying now being what will end up reflected in their inevitable vote to further limit or outright end the filibuster.

McConnell maintains a tight grip on his caucus and ending the filibuster for short-term political gain follows a long, Republican arc towards the centralisation and amassing of power. This doesn't hold as true for the Democrats (in part because pro-filibuster Senate Dems can run in primaries on Compromise/Bipartisanship and still get some credit for it), and Schumer has less sway over his caucus' moderate heroes.

I think there will eventually be filibuster reform, but it'll be an expansion of budget reconciliation rather than the end of the legislative filibuster for non-economic issues.

Those types of moderates are having a harder and harder of a time getting and staying in Congress.

[Person Man]

I think largely it would involve gaining a lock on the demographics already trending Democrat, that is suburban white voters, and enormous margins with younger voters who will become a larger part of the electorate as they grow older. Geographically I think a key election to look at would be Alabama Senate 2017. Counties like Tuscaloosa and Madison would have to be consistently (non-Atlas) blue, and minority turnout would have to be consistently high. For Democrats to actually dominate a party system like this, results like in Alabama would need to be a consistent thing in other now reliably red states. Counties like Tulsa OK and Greenville SC would have to flip, with Republicans really having any standing only in white rural areas.

Of course this is all hypothetical. The counterpoint for Republicans would be to look at Charlie Baker and Larry Hogan win maps in Massachusetts and Maryland. Essentially it boils down to if either party can completely win over white suburban voters, then that party would dominate.

If Democrats can make that sort of coalition in the south sustainable combined with the religious right fading in relevance, say by succeeding in getting roe v wade overturned and essentially winning on abortion after they already lost on gay marriage I could see it.

The religious right is organized around very broad based racial and cultural grievances, not the singular issue of abortion, which conservative Protestants discovered they cared about in the 1970's. So that would never fly. Moreover, Northern cosmopolitans would never accept such an outcome, so the fight would continue indefinitely.

Two things I heard-
1) It was either Jerry Falwell or Pat Robertson who once said that abortion was a Catholic issue as late as 1970?
2) Any outcome where Roe gets overruled PROBABLY makes abortion a bigger issue at least for a few years. Until and unless secular progressives or traditional nationalists are willing to say "it's the law of the land. It's that way for a reason, OK? Period!" and cede the issue , we will see an major policy changes causing a lot of resistance.
3) It will be a HUGE task to get working class rural people to assimilate more into broader society, whether they are minorities or white. Especially to the point where they just see themselves as working people at the level they don't feel guilt voting for their self-interests.