What do you mean holding hostage?

The only leverage points, as mentioned earlier, are a government shutdown or refusing to move the debt ceiling. Both of which are just "we are willing to inflict massive pain until our demands are met." That's what hostage taking is.

Other than that, the Dems have no political power until they win in the midterms.

had just gutted healthcare and other public services

These are political complaints. You've moved from "we have to stop fascism" to "I disagree with these policy choices" which is a vastly different arena. I disagree with the policies but more Americans voted for the administration to enact sweeping policy changes, that's democracy even when the results are other than what you wish they were.