I think there's a (cynical) strategic argument to make that Democrats are making a mistake by choosing popular policy to center this shutdown fight around. They are, in effect, trying to protect Trump's voters from the consequences of voting for Trump. They'd likely be better served electorally by letting it happen, and letting Trump eat the blowback.
It'll be interesting, as the farmer payments are now stalled due to the shutdown... that might put a bunch of farmers under.