Here are five reasons same-sex marriage should be legal nationwide.
First, the government shouldn't have any say in adult personal relationships. It's not the business of the government to decide whom you should spend the rest of your life with or to decide which relationships are "right" or "wrong."
Next, the United States is a nation of many different religions, most of which are mutually exclusive. In other words, Christians don't think the religion of Islam is a true religion and vice versa. Despite all of this, the government still gives tax exceptions to both religions and recognizes them as such. Marriage should be treated the same way.
Third, granting someone else rights doesn't take away anything from your rights.
Freeing the slaves didn't make the rest of the population less free or giving women the right to vote didn't make the votes of men worthless. In fact, it only affirmed these rights as universal and true.
Next, the issue is a human rights issue. When people are not equal in a country that claims everyone is, there is a problem. Our nation's history is full of one group of people trying to stop another group of people from having the same rights as them. It's wrong.
Last, marriage is something familiar to everyone, even gays and lesbians. Gays are born and grew up with parents who more likely than not were married (at least for some portion of their lives) or their grandparents were married.
Gays aren't aliens to the world and culture. Everyone knows when you love someone and want to spend your life with them; you want to marry them - not civil union them. Separate is not equal.
We should all have the right to pursue happiness, no matter how you feel about homosexuality.