Since the early hours of 2014, there has been a flurry of activity in the courts over state bans on same-sex marriages. On New Year's Eve (apparently while also presiding over the ball drop in New York City), Supreme Court Justice Sonia Sotomayor granted a request by the state of Utah to temporarily block same-sex marriages, after a federal judge struck down a law prohibiting them in the state.

Utah is just one of 33 states that have banned gay marriage. Those states have found themselves under legal assault since the Supreme Court last year struck down a portion of the Defense of Marriage Act and allowed Proposition 8, California's ban on same-sex marriage, to be nullified.

Whatever happens in Utah, it's likely to have a domino effect in other states. In Oklahoma, for starters, a different federal judge struck down a similar state law, but blocked gay couples from marrying until a federal appeals court rules on the Utah case.

The number of lawsuits challenging the constitutionality of these bans continues to grow — in the last two weeks alone, attorneys representing same-sex couples in both Florida and Arizona have filed new challenges — making it very likely that the fight will ultimately make its way back to the Supreme Court.

As Lyle Denniston explained at SCOTUSBlog, the Supreme Court's decision to block Utah's marriages indicates that the justices are indeed watching the legal wrangling closely. "The ruling can be interpreted as an indication that the court wants to have further exploration in lower courts of the basic constitutional question of state power to limit marriage to a man and a woman," Denniston wrote. "Had it refused the state's request for delay, that would have left at least the impression that the court was comfortable allowing same-sex marriages to go forward in the 33 states where they are still not permitted by state law."

Until the Supreme Court agrees to hear one or more of these cases, the issue will continue to play out in the lower courts. Here are four hot cases to watch:

1. Virginia
Though two challenges to Virginia's ban on same-sex marriage have been proceeding for some time, in the past few months the atmosphere surrounding the lawsuits has shifted completely. After years of Republican Gov. Bob McDonnell and uber-conservative Attorney General Ken Cuccinelli leading the state, in November voters elected Gov. Terry McAuliffe and Attorney General Mark Herring, Democrats who both support same-sex marriage.

Last week, Herring announced that he believes the law is unconstitutional, will not defend it in court, and is joining one of the two lawsuits to overturn it. "The Commonwealth will side with the plaintiffs in seeking to have the ban declared unconstitutional," he said in a statement. This case is scheduled for a hearing this week.

Aside from being one of the most imminent court fights over gay marriage, adding to the drama in Virginia are some of the players: The lead attorneys for the plaintiffs are David Boies and Theodore B. Olson, the same pair that brought the challenge to Proposition 8 to the Supreme Court.

2. Michigan
U.S. District Judge Bernard Friedman says he will hear arguments on Feb. 25 in a lesbian couple's challenge to Michigan's ban on adoption by same-sex couples. The lawsuit also challenges the state ban on gay marriage as a whole, which was passed by voters in 2004 as a constitutional amendment that defines marriage as being between a man and a woman. Attorneys representing the state have argued that "Michigan supports natural procreation and recognizes that children benefit from being raised by parents of each sex who can then serve as role models of the sexes both individually and together in matrimony."

However, Friedman has referenced the Supreme Court's DOMA decision in the past, explaining that he allowed the couple's case to go to trial because the high court "has provided the requisite precedential fodder for both parties to this litigation."

Just don't take that to mean this case is a done deal in favor of the plaintiffs. "I am in the middle," Friedman says of the case. "I have to decide this as a matter of law."

3. Pennsylvania
Pennsylvania is the last state in the Northeast holding out on legalized gay marriage. But there are a whopping seven lawsuits (at least) circulating in the courts. Each challenges various aspects of the 1996 law, which defines marriage as being between a man and a woman and does not recognize same-sex marriages performed in other states where they are legal. One suit, brought by the ACLU, is scheduled for a hearing in June.

On a political level, these court cases are threatening to make things a tad contentious in the capital. As in Virginia, Pennsylvania's new Democratic Attorney General Kathleen Kane announced just a few weeks after taking office that she will not defend the ban in court. "I cannot ethically defend the constitutionality of Pennsylvania's version of DOMA," she said. "I believe it to be wholly unconstitutional."

Unlike Virginia, however, Pennsylvania's governor is a Republican. Tom Corbett is an uneven opponent of LGBT rights, though still an opponent: He has said that he will defend keeping the gay marriage ban on the books, and in the past has compared same-sex marriage to incest. But recently he changed his position on a bill banning discrimination based on sexual orientation, announcing his newfound support.

4. Ohio
Back in December, Ohio District Judge Timothy Black invalidated part of the state's ban on same-sex marriages, overturning the state's refusal to recognize marriages that occur in other states where such marriages are legal. "That is, once you get married lawfully in one state, another state cannot summarily take your marriage away, because the right to remain married is properly recognized as a fundamental liberty interest protected by the Due Process Clause" of the Constitution, he wrote in his opinion.

The state has said it will appeal this decision, and the narrow nature of Black's ruling means that Ohio's own ban on same-sex marriage is safe for now. But Black also noted in his ruling that this may not be the case for long: "[A]lthough the question of whether Ohio's refusal to grant same-sex marriages also violates Ohio same-sex couples' right to due process and equal protection is not before the court in this case, the logical conclusion to be drawn from the evidence, arguments, and law presented here is that Ohio's violation of the constitutional rights of its gay citizens extends beyond the bounds of this lawsuit."