What happens when states move in different directions from the federal government and their laws collide?
That scenario unfolded in Maryland and Washington state this week where marijuana and same-sex marriage are now legal.
It's been a good week for those who enjoy marijuana and for those who want to marry someone of their same gender.
In Washington state, people openly lit joints under Seattle's Space Needle, celebrating its legalization. Colorado will follow suit next month.
Also in Washington and in Maryland, same-sex marriage licenses are now available after voters approved gay marriage in November.
"Now that it's happening, I'm happy," said Joanne King, who is applying for a gay marriage license. "I'm excited. I'm nervous. I can't wait until all of this is over and done with."
But with both these social issues comes a very complicated legal dance with the federal government.
The Justice Department still maintains that marijuana remains illegal under federal law. And federal law also defines marriage as only between one man and one woman, meaning federal benefits only apply to those in traditional marriages.
The U.S. Supreme Court at some point will likely decide the issue of gay marriage for the country. But with 32 states that have traditional marriage amendments on the books, it may take its time.
"This is fundamentally a religious liberty question," Brian Brown, president of the National Organization for Marriage, said.
"Redefine marriage, you redefine it for everyone and the law will be used to punish and marginalize those of us that believe marriage is the union of a man and a woman," he warned. "It's already happening."
Meanwhile, a Nevada district court recently issued a ruling to uphold the state's ban on gay marriage. The judge ruled Nevada has a legitimate state interest in mainting traditional marriage.
As for marijuana, it's difficult to see how the new laws will play out. For instance, the feds could easily raid state-licensed growers and stores.
Constitutional law experts say when state and federal laws conflict, the feds win. That may mean the Justice Department sues to block the states' regulation of marijuana.
So far, the agency has given no hints about its plans.