Doing so would have played into Trump’s hand, knowing that the passage of time dilutes public interest and allows false narratives, repeated over and over by Trump and State TV, to become acceptable “truth.”
Good lawyers don’t overtry their case. Get the case to the jury sooner than later.
Schumer is wisely forcing McConnell to pass on key witnesses — Bolton, Mulvaney, Pompeo, etc.
Keep pretending they have nothing to hide.