There are 2 somewhat different points to be made
1. Congressional subpoena. Is it worth more than the paper it is written on or not?
2. Impeachment in the face of presidential criminal behavior.
In my opinion we should be enforcing both. Yes I understand there is the current political reality. However, somewhere down the road, regardless of the current political winds, the citizens of the country will be judging this moment. As a citizenry, as a government, we will either enforce the rule of law or we will cede it to even greater corruption.
I believe we can do all 3 things.
Uphold the value and integrity of congressional investigations as a constitutional balance to presidential and judicial misconduct.
Use impeachment as a tool to rid the highest office in the land of extreme corruption.
Sweep the next round of elections and turn the tide back toward the general welfare of the American people.
You can say I'm a dreamer, but I'm not the only one.
