Bathrooms didn't seem like a huge issue just a few months ago, but it now seems like they have turned the 2016 presidential election into a very crucial one for LGBTQ rights.

LGBTQ rights have always been an important aspect of the presidential race, of course. But the recent debate over bathrooms and whether transgender people, who identify with a gender different from the one assigned to them at birth, should be able to use the facilities for their gender identity has elevated these issues.

The critical turning point came on Wednesday, when 11 states filed a lawsuit against the Obama administration in an attempt to halt a federal guidance telling public schools they must let trans students use the bathroom and locker room for their gender identity.

At first, this may seem like just a scuffle between the Obama administration and a few states. But chances are this legal battle will drag on, potentially ending up at the Supreme Court in the next few years. And since the Obama administration won't be around by then, whoever is in charge of the next administration will play a huge role in how this legal battle plays out — and whether there even is a legal battle.

To understand why that is, you first have to understand the underlying legal dispute behind the 11 states' lawsuit. So let's back up a bit.

What the legal battle behind the transgender bathroom issue is about

The central dispute here is over federal civil rights laws. The Obama administration argues that federal civil rights laws that ban sex discrimination, such as Title IX (for schools), also protect trans people, because anti-trans discrimination is rooted in expectations of what people of certain sexes should be like. The 11 states, led by Texas, disagree. With the issue now in the legal system, the courts will decide who's right.

But this isn't necessarily just about trans people. The full interpretation of federal civil rights laws, LGBTQ advocates have long argued, is that even gay people are protected by existing federal laws, since, similarly, anti-LGBTQ discrimination is rooted in expectations of what people of certain sexes should be like. (For example, that a man must love a woman.)

In other words, if interpreted one way, federal civil rights laws should already protect LGBTQ people from discrimination on the basis of sexual orientation or gender identity in the workplace, housing, and education. (This doesn't include public accommodations, such as restaurants, hotels, and other places that serve the public, because federal law does not ban sex discrimination in those settings.) That would be huge, as federal law and most states' laws don't explicitly protect LGBTQ people right now.

Why the legal battle matters for 2016

The first reason this legal battle matters for 2016 is the election will decide whether the next administration even makes this an issue. After all, if the White House wasn't pushing for a broader interpretation of federal civil rights laws, there wouldn't be a lawsuit. So if Hillary Clinton becomes president, she will likely continue pushing this interpretation, and this is therefore much more likely to continue being an issue for states to sue over. If Donald Trump becomes president, probably not.

But chances are this will play out in the courts anyway. LGBTQ advocates — backed by the federal Equal Employment Opportunity Commission — have pushed the pro-LGBTQ interpretation of federal civil rights laws for years, and filed several legal challenges to that effect. One way or another, then, this is likely to go to court.

If that's the case, this issue will likely end up appealed to the Supreme Court in the next few years. So the nation's highest court could decide if LGBTQ people really are protected under existing federal civil rights law from discrimination in the workplace, housing, and education.

If that's the case, it will be all the more important who gets to nominate justices to the Supreme Court. We already know that the next president will very likely get one pick to replace the deceased Justice Antonin Scalia. But two other justices will be more than 80 years old by Election Day — surpassing the average retirement age for justices. So the next president could find herself or himself nominating as many as three people to the Supreme Court, deciding one-third of the Court's makeup.

Needless to say, President Clinton would likely nominate justices who are friendly to LGBTQ rights, while Trump indicated that he'd nominate fairly conservative justices who would likely be less friendly to LGBTQ equality. With potentially several Supreme Court seats to fill, this distinction could very well decide the future of LGBTQ rights.