I don't know what you mean by "no one to replace Boeing with," if you have a different criteria or not, but a quick Google search shows there's at least three more companies in the industry. I always thought it was just Airbus, but apparently not.
Still doesn't change the fact that another Trump presidency could literally allow Boeing to get worse without repercussion and encourage other companies to keep cutting even more corners.
I've seen plenty of blues fight hard against Sanders and Warren, Dems and the left were literally at war with each other in 2016.
If you vote for policy, then why would you vote for Trump when you just said he's a racist? Do you agree with those policies?