There's only so much Trump's lawyers can do with the way he handled things.
I don't think the Senators that are standing up for Trump realize that it's not even a problem of bad lawyers, though:
Dozens of former Bush officials leave Republican Party, calling it 'Trump cult' It's a crossroads for the GOP. They've been edging further and further to the right for the last decades, but now they have come to a reckoning. They either become a white supremacist party or they return to their roots.