Democrats should not oppose Trump’s wall.
First of all, there is no reason to oppose it other than “fiscal responsibility”, and it will be bizarre for them to take on this particular banner.
Second, it’s clear that very many voters want it. There needs to be a pretty powerful reason to oppose such a passionate wish, and “fiscal responsibility” isn’t it. Especially for a party that has been ridiculing the concept for years.
Third, Trump needs a signature achievement. You don’t give him a useless but inoffensive wall, he’ll be looking for an achievement elsewhere.
There is literally no downside to the wall other than some money being wasted. But this country wastes a lot of money on crap already, so what’s the big deal?
Smart Democrats in Congress would unanimously support funding the wall because this is a ridiculous, senseless battle to wage.