Let's not forget why Trump was so confident in his efforts to overturn the election results

[bigtree]

8. need solid evidence of criminality to get a warrant

...a talking witness.

Or, some documents.

The Supreme Court has zero legally enforcable rules of conduct regarding gifts and other favors. Moreover, they just legalized bribing politicians.

The most realistic means of accountability is through impeachment which would take a sufficent majority in the House and in the Senate to convict.