Compact to award electoral votes based upon national popular vote

Connecticut just passed a bill enabling this, but is it legal?

No, it should not be.  Yet, who knows these days?  The liberals will not respect the constitution unless there is an advantage to them.

This would be illegal because of prohibition upon states of entering into compacts with another state.

Article 1, Section 10

No State shall, without the Consent of Congress, lay any duty of Tonnage, keep Troops, or Ships of War in time of Peace, enter into any Agreement or Compact with another State, or with a foreign Power, or engage in War, unless actually invaded, or in such imminent Danger as will not admit of delay.

It's a controversy waiting to happen.