Not too long ago, a way of life that once seemed unimaginable started to become a reality for millions of Americans. Surfacing slowly in different states, it began to seep across the country, shedding its stigma and compelling politicians to edit their long-established talking points. Eventually, it gained the support of a national majority.

Thinking of gay marriage? Guess again. The once-controversial issue that has reached a tipping point on a national scale this time? Marijuana legalization. And pot smokers throughout the country have plenty of reasons to celebrate.

Popular belief in the early 20th century held that marijuana was a substance that led to rape, murder and madness. But today people are lighting up for fun in Colorado and Washington. Legalizing recreational use is on the ballot in Oregon, Alaska and Washington, D.C. for the midterm elections in November, and the future of legal weed in many more states burns bright.

In fact, most Americans now support legalization, as can be seen in the chart below:

CNN ' ORC Poll

Pop culture can be subversive: Pop culture relentlessly reshapes the national imagination and the contours of our political consciousness, and it has slowly worn down the idea that gay marriage threatens society in a way that party politics could have never accomplished. Similarly, pop culture has altered the reputation of marijuana by rendering it generally harmless, and in the process paved the path for its legal normalization.

The Democratic Party's piecemeal enlightenment on gay marriage has been steadily building since at least 2004, when Democrats ended up taking stances on civil unions at the national level, but gay couples have been hinted at and depicted in popular culture for far longer. Think about the homoeroticism permeating The Great Gatsby, or how gay couples have appeared in some form or another on film and television since 1972, or Elton John telling Rolling Stone in 1976, "There's nothing wrong with going to bed with somebody of your own sex."

By the turn of the millennium, gay couples were featured on prime-time television shows like Will and Grace. This kind of presence emboldened the gay rights movement and acted as an incubator for expanding certain notions of equality and fairness before they were prepared to hit the political main stage.

In the last couple of decades, smoking marijuana has emerged from private life and stoner culture and broken into the mainstream in films and popular shows like HBO's Weeds. Its representation in comedy has defanged its image, and unless you have your head buried in the sand, it's clear that the worst sin we can accuse someone who likes to smoke weed of is being kind of lazy and eating too much.

This spectacular montage by Eclectic Method captures some of the essential moments of marijuana use breaking through in pop culture:

Different states, different stakes: While it's common to lament the way our nation's unbridgeable cultural differences contribute to gridlock in Washington, the benefit of living in a massive federal republic is that smaller communities within it can experiment with new ways of life without infringing on others. In other words, America's combination of largeness and localism are a natural recipe for cultural and political pluralism.

While supporting marriage equality on the federal level was inconceivable in the early 2000s, some states were able to make reforms considered unthinkable become a reality. In 2004, Massachusetts became the first state to legalize same-sex marriage, and when it didn't transform into an anarchic bastion of pedophilia and bestiality (I'm not sure what a homophobic dystopia is, but that's an attempt), it served as a living, breathing case study that other states could taken note of. As state after state takes the plunge, a domino effect begins to take hold as people realize the naysayers were crying wolf. Today, more than 30 states and Washington, D.C. allow marriage for same-sex couples.

Marijuana is currently legal for medical purposes in close to half of the nation's states. Given that Colorado and Washington's introduction of recreational marijuana has left those states unscathed, it's likely other states will soon follow suit with full legalization.

Never say no to money: While legalizing gay marriage isn't a conventional money-maker, many pieces of evidence prove it's good for the economy. The Congressional Budget Office once estimated that if same-sex marriages were legalized in all states and recognized federally, it would result in an extra $1 billion for the budget every year for 10 years. It also has impact on the state level — a year after New York passed same-sex marriage, gay marriage generated over $250 million in New York City alone.

There's also the political fact that once a movement becomes powerful, politicians, ever hungry for cash, will begin to eye them, and eventually, fearing the money could go to an opponent, will compete for them. Favors are exchanged, and everyone gets what they want (at least some of the time). Many political observers believe the power of the LGBT donor machine accelerated President Barack Obama's evolution on gay marriage.

There's money in marijuana, and lots of it. Legalizing, regulating and taxing it is a multibillion-dollar revolution sweeping the country. State budgets are in terrible shape, and it's hard to see how legislators torn between cutting funding for vital highways or educational programs for low-income households are going to leave money on the table when they realize that legalizing marijuana is virtually guaranteed to bring in a large, steady flow of cash.

And regarding the point of national politicians becoming willing to support something controversial once it can bring in enough money: The marijuana industry is already worth tens of billions of dollars, and estimates suggest it will be worth $35 billion in 2020 if nationally legalized.

Never underestimate a small step: Not too long ago, gay marriage was an idea that had very dim prospects nationally. But it serves as a useful example of how an idea can percolate in civil society and how dozens of small measures on the state level can accumulate into a wave of momentum that makes something go from taboo to common sense in a relatively short period of time.

Marijuana appears to be taking the path that acceptance of gay marriage forged, and that's a great thing for everyone.