Warren might be replaced by, say, Richard Tisei. Worst case scenario, Tisei holds the seat in a special election and 2018 and then maybe is the sixtieth GOP Senator.
I'm sure Baker would pick Tisei theoretically, but the MA Democrats have a veto-proof majority in the legislature, and they could pass a law preventing Baker from choosing a Republican.
What's happening? Does everyone here think Deval Patrick appointed Scott Brown? Is everyone here too young to remember 6 years ago?
The special election would happen about a month after Hillary is sworn in. This compares with Tim Kaine, whose seat would probably be filled by special election next year. But it'd be easier for Democrats to win the Massachusetts special than the Virginia one. Unless maybe Massachusetts Democrats nominate Martha again. As far as holding a senate seat longer term, Murray or Klobuchar seem better choices, and of course Perez sacrifices no seat at all. Brown, Nelson, Heinrich can't happen.
Kaine supports Trans Pacific Trade and Clinton is against it.
She'll be for it again as soon as she clinches the nomination. Also, this wouldn't matter.