On Tuesday, Philadelphia’s transit workers went on strike, halting all bus, trolley, and rail service in the city. And, given the time of year, lots of people are wondering how this might affect the presidential election. Pennsylvania is a key swing state, after all.

The short answer is that this probably won’t matter much, though there’s always a chance. Democratic Congress member Bob Brady told the Philadelphia Inquirer that Hillary Clinton’s campaign has at least “a little concern.” So let’s take a look.

First, the strike itself: The union in question is Transportation Workers Union Local 234, which hasn’t yet reached agreement on a new contract with SEPTA, the regional transit authority. The last contract expired at midnight on Monday. There are three major sticking points: pension caps, health care benefits, and a dispute over employee scheduling — the unions says new bus drivers often get wildly irregular shifts, swinging between late nights and early mornings, which can case fatigue and accidents.

How it could affect the election: If SEPTA were still shut down on Election Day, it’s unclear how many people would be barred from voting. There’s some reason to think it might not matter much: Many Philadelphia residents do live within walking distance of their nearest polling place. And the Philadelphia Board of Commissioners says that a 2009 strike lasting through a local election didn’t really hurt turnout.

But there’s also reason for worry: This is a presidential election, and many more voters are coming out than in a local election. And about 900,000 people, or 10 percent of Philadelphia metro residents, rely on SEPTA for their daily commuting needs. If they have trouble getting to work that day, it’s possible they might not have time to vote. Note that in other presidential elections, about 5 percent of registered voters who didn’t vote cited “transport problems” as the reason. So you can see why Clinton’s camp might be concerned, especially if this is more likely to hinder low-income Democratic voters with fewer transportation options.

But before anyone starts panicking, there are two other points to consider:

1) The strike might not actually last through next Tuesday. SEPTA and TWU 234 could conceivably come to an agreement before then and none of this will matter. Note that the last SEPTA strike, in 2009, only lasted six days.

2) If the strike is still going on as of November 8, SEPTA has said it could seek a court injunction to stop the strike temporarily. What that means, as Anna Orso explains here, is that SEPTA would have to convince the Philadelphia Court of Common Pleas that the welfare or safety of the public is at risk in this strike. The court could then order union transit workers back to work for the day, and the order would be enforced by the Philadelphia Sheriff’s Office. (That said, it’s not clear SEPTA would win this argument.)

In a statement, the Clinton campaign simply said: “We are hopeful that both sides can come to an agreement in short order." But this is worth keeping an eye on. Note that current polls have Clinton up by about 5 points in Pennsylvania, a state Trump would love to win and that she can’t really afford to lose.