There is only one thing left blocking a full blown constitutional crisis.

[dixiegrrrrl]

2. we are on dangerous ground now.

the dictator playbook calls for the removal/neutralizing of Congress/Parliament/etc. and of the courts.
The Senate is still siding with trump,
SCOTUS is a tossup, and some of the Federal courts now have trump allies installed
and now trump is trying to neuter the House .

If these guys are ignoring Congressional subpoenas, they will also ignore consequences, short of jail. Maybe even jail will not faze them.
recall all the mob movies where a fall guy goes to jail to protect bigger fish.

and while all these maneuvers are going on, the clock is ticking on the statute of limitations for trump's various Obstruction charges, which, as Rachel pointed out, will expire in 2021 and 2022

If the Dems wimp out about consequences for contempt, game over.