It's very easy these days to point and laugh at the Republican Party and mock it for getting itself into its current position. Years of a cynical leadership promoting supply side economics while throwing some culture war bones to supporters getting screwed by those economics created a base so rabid that it can no longer be controlled, and can be easily swayed by a Trumpian demagogue. The bill for decades of double-dealing has finally come due.
Because the Democrats are not imploding as spectacularly, it is easy to overlook their current mess. Their party's clear standard bearer has been losing states to a cantankerous outsider with few presidential bona fides who until recently held office as an independent socialist. The most enthusiasm from the base is coming from his supporters, even though he's not even really a Democrat. More crucially, while Republicans have turned "red" states like Louisiana and Kansas into one party governments capable of maintaining power even after running their states into the ground, Democrats have lost control of "blue" states like Michigan, Wisconsin, and New Jersey. This has led to once impossible things, such as Michigan becoming a "right to work" state. Clinton is 69 years old, Sanders is 74. The party's failures on the state and local level have left it without a new generation of Democrats in office. Who the hell would even be able to run in 2020 with any real national following?
The crisis runs even deeper than these tip of the iceberg symptoms of decline. The Democrats have been getting squashed in midterm elections, effectively squandering the Obama presidency as the Republicans have gone into full-on resistance mode. The scene was set back in 2009, when the screamers and ranters went out to berate politicians who supported the Affordable Care Act, leading to the Tea Party midterm of 2010. As the current election has shown manifestly in the case of Jeb Bush, lots of superPAC money won't swing a presidential election by itself. However, in Congressional races, it makes a huge difference. With corporations solidly in the Republican camp, the Democrats play at a huge disadvantage when it comes to winning Congress. After that 2010 sweep, they also got to redraw electoral maps and gerrymander several states. On top of all of that, the Supreme Court invalidated parts of the Voting Rights Act, enabling voter suppression on a massive scale.
The only way for the Democrats to overcome these obstacles is by increasing their turnout, especially in off-year elections. Voter suppression makes that hard, as well as the fact that the Democratic party does so little for its base. Teachers and their unions are supposed to be a part of the coalition, but Democrats consistently enact education "reforms" contrary to what teachers want. It's as if Republicans passed major regulations on oil companies then expected their usual support. Latinos support the Democrats, but when the party had both the presidency and Congress, it increased deportations rather than push through comprehensive immigration reform. African-Americans vote overwhelmingly Democratic, but the party has been slow to move against mass incarceration after spearheading such efforts in the 1990s. How do Democratic politicians expect to win if they refuse to do the things their voters put them there to do? Is someone really going to be motivated to go out and vote in an off-year election for a candidate who will give them nothing but lip service?
The Democrats have been able to console themselves with presidential wins, but the current favorable conditions won't last forever. A nightmare scenario could be coming. Trump could well be the nominee, then go down in flames in the general election. That might give the Romney wing of the party the ability to say "see I told you so" and push the party in a more moderate direction, especially on immigration. If the Republicans are able to pivot on those issues while not totally losing their base, the Democrats will be in deeper trouble. I'm not putting any money on this, but this is a party whose success has more to do with the dysfunction of their opponents than any other quality. That's not a good place to be.