Trump threatens to dump illegal migrants into Sanctuary Cities to punish congressional foes for inaction on the border...

but wouldn't that hurt him more than help him?

It wasn't too long ago that he was against sanctuary cities claiming they violate federal law, now it appears he's for them. Not only that, but his promise to protect the innocent Americans from the crime thirsty illegals by imposing his immigration policies to keep them out, now he threatens to release them.