House Democrats control almost 2/3 of seats (121/188) representing 18 of the most export-dependent metros, and the amount of Democratic voters living in manufacturing-dependent cities keep on declining, already down 50% from 20 years ago.
Arguably, the labor unions have the strongest anti-TPP GOTV in those districts by far, & they'll eventually back down if she comes out pro-TPP since they don't have organic votes in those districts, and they won't be able to compete with her GOTV & comms. Without anti-TPP union GOTV efforts in those districts, there won't be enough incentive to vote against.
Fact is, she won't jeopardize House Dems since she'll need as many as she can get. Plus, she'll have bipartisan cred on two bipartisan initiatives in her first term: prison reform & TPP, and she'll even neutralize many GOPers.
To assuage progressives, she'll embrace EU Trade Envoy Cecillia Malmstrom's ISDS reform proposal. [this one is trickier though in terms of votes & targeted comms]
** This is neither pro-TPP or anti-TPP. Just my assessment.