Just like marriage equality happened state-by-state (Massachusetts, Vermont, Iowa, and then many more) and eventually led to the U. S. Supreme Court decision in 2015 that made it national, “Reality beat the prejudice” when it came to both marriage equality and legalizing marijuana, as former Congressman Barney Frank puts it in the clip below.

And he should know. Not only has he been a leader of the marriage equality fight, he introduced a bill during Nixon’s presidency to decriminalize marijuana after Nixon’s own commission found very little, if any, harmful effects. That was more than 40 years ago.

Take a gander at this graph:

Marijuana Legalization And Marriage Equality Trajectory

These are over a 19-year period, from 1996 to 2015, using Gallup polls titled, respectively, "Do you think the use of marijuana should be made legal, or not?" and "Do you think marriages between same-sex couples should or should not be recognized by the law as valid, with the same rights as traditional marriages?"

It’s a sign that our cultural shifts can follow similar trajectories and lead to massive shifts in public opinion over a relatively short period of time.

With 19 states now legally medical marijuana states, and 5 legally recreational marijuana states, it's in a similar place as it was just a year or two ago for marriage equality. And with the coming elections, even more will follow suit. And then, there will likely be the Supreme Court case that decides it for the country. Let's hope that it's a court that is friendly to progress and not mired in regress.

Barney Frank illustrates some of how this came to be and why it's similar to marriage equality in this fascinating clip:

For more from and about Barney Frank, here's a link for you.