Notably, advocates of reforming marijuana laws made progress in regions of the country they'd previously had little success in. On the medical marijuana sign, Florida became the first state in the South to approve a robust medical marijuana proposal. Arkansas soon followed suit, a surprising development given the chaotic history of the measure -- two separate proposals were actually on the ballot there, but due to a late court ruling only one could be voted on.
Another surprise in the medical marijuana space was deep-red North Dakota, where nearly two-thirds of voters cast their ballots in favor of medical pot. That contest flew so far under the radar that there wasn't a single poll conducted on the question.
Neighboring Montana had initially approved of a medical marijuana way back in 2004. But since then state lawmakers had steadily chipped away at the measure, eventually passing strict new rules that would have shut down many of the state's dispensaries.
This year, medical marijuana supporters put an item on the ballot to roll back most of those restrictions. Polls seemed to indicate voter skepticism, with 51 percent opposing the ballot measure as recently as October. But in a surprising twist, they ultimately passed the measure by 58-42.
On the recreational marijuana side, one of the biggest surprises was a strong showing in favor of legalization in Massachusetts where voters approved the measure by a strong 54-46 showing. Political and businesses leaders had come out swinging against the proposal earlier in the year. They were bolstered at the last minute by an 11th-hour donation of $850,000 to the opposition campaign from the Archdiocese of Boston. But most voters were unswayed by the arguments against marijuana.
Maine's contest was the closest on the recreational marijuana side. But voters there ultimately passed legalization by just a few thousand votes. With the votes in Massachusetts and Maine, marijuana reformers have won their first major legalization battles on the east coast. Those victories could set the stage for efforts to legalize marijuana in other New England states via state legislatures in the coming years.
On the other side of the country, Nevada voters also approved recreational marijuana by a margin of 54 to 46. Casino magnate Sheldon Adelson almost single-handedly funded the opposition to legal pot there, giving a total of $3.35 million to legalization opponents, or about 97 percent of their total fundraising.
Adelson's bet against pot paid off better in neighboring Arizona, where voters shot down a legalization bill by 52 to 48. Adelson gave half a million dollars to the opposition campaign in Arizona, joining forces with a number of local business interests.
But the biggest news of the evening was the decisive 56-44 win for legal marijuana in California, the nation's most populous state and itself one of the largest economies in the world. With the vote in California the use of marijuana will become legal down the entirety of the west coast, from the Mexican border to Canada and up again to Alaska.
The victory for pot in California means that dozens of legislators in the U.S. House will soon represent the interests of a growing California-based marijuana industry, making a congressional push to resolve differences between state and federal marijuana laws all the more likely.
All told, nearly one quarter of U.S. residents will now live in states that allow the recreational use of marijuana. President Obama recently predicted that this situation would make strict federal policies toward marijuana untenable.
"You'll now have a fifth of the country that's operating under one set of laws and four-fifths in another," he told Bill Maher. "The Justice Department, DEA, FBI, for them to try to straddle and figure out how they're supposed to enforce laws in some places and not in others... that is not going to be tenable."