‘A number of states colluding against the others.’
no one is colluding against anybody; you’re assuming the 270 EV’s are all going to one candidate; states are perfectly free to vote as they wish, and red states can attempt to win the popular vote by turning out more voters...
the real problem here is that the GOP does not appear capable of winning the popular vote...
Actually no, they can’t. States are actually not allowed to make deals with each other against other states without permission from Congress.
That’s to prevent situations where certain states could hog resources and control certain monopolies.
So this idea would be unconstitutional unless Congress approves of it since you have a number of states making a deal with each other. Not to mention you can see the intent is to go around the Constitution. The Constitutional has an electoral college. If you want it by popular vote, you need to get rid of that through the amendment process.
The Supreme Court would kill this whole thing.