California and the feds are at it again, this time over clean air and Quebec

The United States on Wednesday sued California for entering a climate agreement with Canada's Quebec province, saying the state had no right to conduct foreign policy, in the latest feud between the Trump administration and the state. President Donald Trump's administration argued in the lawsuit that California's 2013 agreement to link its emission-trading program — the centerpiece of its climate-change policy — to Quebec's violates the U.S. Constitution, which prohibits states from making treaties or pacts with foreign powers.