Some think the newly fallen pot-domino states will make it too difficult for the U.S. Department of Justice to attempt to enforce the federal law. Ethan Nadelmann, executive director for the Drug Policy Alliance, said in a statement to The Washington Post the state results were "a monumental victory for the marijuana reform movement. With California's leadership now, the end of marijuana prohibition nationally, and even internationally, is fast approaching."

But other experts aren't so sure the Justice Department won't test enforcing the federal law. Currently, state legalization and the already existing "legal" pot businesses in those states are relying on a pair of Obama administration memos for their security. The memos defined a strategy under which the Justice Department would essentially look the other way at activities in states where  pot is legal, and also on Indian reservations in those states. (In theory, because reservations fall under federal, not state, law, the feds could shut down an Indian growing operation in a state where pot is legal.)

Now, warns Robert Miller, a professor at Arizona State University's Sandra Day O'Connor College of Law and an appellate judge for the Grand Ronde tribe in pot-legal Oregon, all the projects could be in jeopardy.

"The legal questions cause uncertainty, and business and investment hates uncertainty," Miller told Oregon Business magazine. Miller, who is also the author of "Reservation Capitalism: Economic Development in Indian Country," notes Trump has been inconsistent in his support of the memos and of state legalization. He could decide to offload the decision to a new attorney general, who might find a fight refreshing.