You bought it. You're who they're pandering to. All Democrats and anyone who hates Trump.
Yes, it is political posturing. Or, the House Democrats are dumber than originally thought.
Firstly, their point for the alleged subpoena makes an issue of the separation of powers.
Furthermore, Trump has every right due to the scope of the subpoena, i.e. they want his tax returns, to claim Executive Privilege.
If the HWM bellyaches about that, as they likely will, it can go to SCOTUS. SCOTUS has to then review the scope of the subpoena , which would be Trump's private tax returns, and there the case of
United States v. Nixon would come into review.
Which means, while the House can subpoena a ham sandwich if they choose, in the SCOTUS matter House Ways and Means would have to prove the returns are essential to the justice of the case, or, a valid legal purpose. Which they cannot do because there is no law that states a member of the Executive have to release their personal tax returns.
This effort is not essential to the justice of any case nor does it have any legal purpose.
The court cannot issue a decision on a fishing expedition. Which this is.