I dispute your claim. Find one person who voted Trump last time who is switching to dems now....many dems are, ARE switching to Trump as we speak.
It does not work that way. Even if everyone who voted for Trump, and a few more would vote for him again, the historic Obama coalition of 2008 will easily sink Trump. And if MO is on the ticket, the 2008 coalition will only increase dramatically.
I think a lot of white suburban women ... formerly called 'soccer moms' ... are getting sucked into the whole BLM virtue signalling thing and at least some will switch from Trump to once again prove they are not racists. They learned nothing from voting for Obama to prove they were not racists. It only works until the dems decide they need to accuse you again to get you back in line.