Even though the Jan 6 investigation had been pre-undermined with a
requirement for Republican agreement to issue any subpoena, most
Republicans in the House voted not to have any investigation.
Democrats compromised by giving Republicans equal representation in
the commission, hoping to win some Republican support. In response to
that, Senator McConnell called it a "slanted and unbalanced proposal."
McConnell can probably kill the investigation entirely.
It was foolish of the Democrats to agree to a compromise without
getting a final deal as part of the compromise. It appears that what
they will ultimately get for their concession is nothing — and
making a concession uselessly only looks weak.