Democrats figured out how to use statewide referenda to their political advantage this year. You have to ask what took them so long, given how central the referendum and initiative process has been to GOP turnout.
This points out something that should be obvious but isn’t: The GOP has been remarkably innovative over the past decades in building its base and achieving some kind of parity. Those innovations, however, can be copied, and once they are copied, the advantage they gave the GOP disappears.
Take turnout as an example. Democrats used a different turnout model from Republicans. They relied on outside groups (labor unions and the like) to boost turnout and paid their laborers for their efforts. The GOP took a more communitarian approach, spending money on technology to identify potential voters but relying on people in the community — unpaid volunteers who were doing what they were doing out of principle or passion or even neighborliness — to get voters to the polls.
The GOP system worked better. So Democrats have copied it. And therefore the GOP advantage in this area no longer exists.
Which is why, again, it all comes back to ideas.