The fight over same-sex marriage is cropping up everywhere right now, and American businesses—big and small—are playing what will end up being significant roles in the debate.

Tuesday, the issue hit an important milestone when the U.S. Appeals Court for the Ninth Circuit declared California’s voter-approved ban on same-sex marriage unconstitutional. "Proposition 8 serves no purpose, and has no effect, other than to lessen the status and human dignity of gays and lesbians in California, and to officially reclassify their relationships and families as inferior to those of opposite-sex couples," the majority decision read.

The court’s decision no doubt speeds up the day the U.S. Supreme Court takes up the matter, something both sides in the emotionally-charged debate want. After all, the states are imposing different standards with legislatures or courts in six states and the District of Columbia approving same-sex marriage while another five states have ok’d civil unions that bestow practically the same rights and responsibilities as marriage. On the other side, three-fifths of the states have specifically said no to the idea, either through constitutional amendments or voter referendum.

What’s fascinating to watch in all of this is first, how businesses are reacting; and second, how interest groups are reacting to those businesses. It’s safe to say that much of the business world has come out, if not totally in support of the “gay agenda,” then pretty darn close. For example, this year for the first time, all 100 firms on Fortune's Best Companies To Work For list have non-discrimination policies that include sexual orientation. And more big-name companies are taking some bold steps forward on the marriage question. Some recent examples:

• Starbucks, Microsoft and Amazon have come out for marriage equality in Washington state, where all three are based. Those decisions have led to calls for boycotts from social conservative groups who believe Starbucks, for example, has turned against God.
• J.C. Penney has incurred the wrath of a group called One Million Moms, an offshoot of the American Family Association, for hiring Ellen DeGeneres as a spokesperson. According to this group, the openly-lesbian DeGeneres “is not a true representation of the type of families that shop at their store. The majority of J.C. Penney shoppers will be offended and choose to no longer shop there.” One of the reasons the group says Degeneres isn’t acceptable: she married her girlfriend, actress Portia DeRossi.
• Goldman Sachs CEO Lloyd Blankfein not only has come out in support of same-sex marriage, but taken the role of the Human Rights Campaign Fund’s first national corporate spokesman on the issue. “America’s corporations learned long ago that equality is just good business and is the right thing to do,” Blankfein says in a video message that was played at HRC’s gala dinner in Manhattan on Saturday night. Protestors also showed up, but in this case they were liberal gays who were angry at Goldman’s "predatory" financial policies.

When it comes to small business, the values and beliefs of the owners really come into play. And here, the issue can get very, very personal. In Hawaii last December, a lesbian couple filed a lawsuit against a bed-and-breakfast owner for denying them a room because of their relationship. A gay male couple took the same action against another inn-keeper in Illinois last September.

In both the Hawaii and Illinois examples, the business people freely said that they opposed homosexuality on moral and religious grounds. Further, they made the case that being forced to cater to a same-sex couple infringed on their own right to religious liberty.

It’s a delicate and tricky matter when you pit two views, both rooted in their own sense of morality and fairness, against each other. And for businesses choosing—willingly or not—to make a stand, one big impact will be how it affects their bottom line.