They could use the levers they have, like the budget. They should have played hardball the first time, but they didn't. They should play hardball this time and shut what's left of the government down but based on what Schumer's saying, I don't think they will. Dem leadership is weak.
How would a shutdown be helpful? You’ve seen how Trump operates. He’ll simply keep the agencies he wants open funded via emergency authority and use the emptiness caused by the shutdown to sabotage and dismantle the agencies they want to torpedo. Easier to kill something when it’s asleep.