Short version: Politicians in places like the PROM and DaFSoNJ* hate the tax cut plan

because it'll make it harder to hide just how nasty their taxes are, and harder to keep the peasants quiet about them.

I flat love this slap of reality:
New Jersey’s Gov.-elect Phil Murphy campaigned on a promise to impose a “millionaires’ tax.” But the Democratic president of the state Senate, Steve Sweeney, said in November that New Jersey needs to “hit the pause button” because “we can’t afford to lose thousands of people.” His next words could have come from a Republican: “You know, 1% of the people in the state of New Jersey pay about 42% of its tax base. And you know, they can leave.”
Yes, they can.  Some of them already are, and it's hurting.  Which is good: stupid SHOULD hurt.

*In case you haven't seen those before,
PROM= People's Republic of Maryland or Massachussetts
DaFSoNJ= Dark and Fascist State of New Jersey