Democracy has two mechanisms that have to function in order for it to be a legitimate democracy at all: voice and exit.
The reason why Democrats are so bad at democracy is because they are champions of quashing exit. It's not a true liberal party at all when you get down to its economic heart. It's a totalitarian party.
The only way to combat this march towards totalitarianism is through the support of the 10th amendment. As the saying goes: good fences make good neighbors.