Philadelphia Eagles running back LeSean McCoy (25) runs against the San Francisco 49ers during the second half of an NFL football game in Santa Clara, Calif., Sunday, Sept. 28, 2014. (AP Photo/Ben Margot)

Update: The FCC has indeed just struck down the blackout rule.

Sports fans who want to see their local teams play on free, over-the-air television are often stopped in their tracks by a little-known rule that forces them to the stadium — or to not watch at all. It's colloquially called the "blackout rule," and if some federal regulators get their way Tuesday, this rule might be going the way of the dodo.

The blackout rule goes something like this: If a stadium fails to sell out for a given game, then the game can't be shown on broadcast TV — nor, by extension, on cable and satellite TV providers in the same area who carry that broadcast content. It affects a lot of pro football games, which is why it's also sometimes called the NFL blackout rule. The idea is that encouraging people to go to games in person helps support the NFL financially.

But a couple of FCC commissioners have been on the warpath lately against the rule, saying it benefits sports leagues and team owners at the expense of ordinary Americans who just want to be fans regardless of how they're watching.

The FCC's blackout "keep[s] hard-working American consumers out of the end zone," said FCC Commissioner Ajit Pai in August. "There is no reason for the FCC to be in the sports blackout business."

The NFL could continue to blackout games on its own without the FCC's support. And repealing the rule probably wouldn't change much for streaming video services, either. But agency chairman Tom Wheeler indicated earlier this month that he's incredulous at some of the arguments the league has put forward to defend the rule. The NFL has hinted that if the rule were repealed, it could drive sports games to be shown exclusively on cable networks, forcing some fans to start paying for cable packages instead of getting to watch the games for free on broadcast TV.

"Believe it or not, the league is actually arguing that it's fighting to preserve the FCC's sports blackout rules for the sake of the fans," wrote Wheeler in a USA Today op-ed this month. "To hear the NFL describe it, you would think that putting a game on CBS, NBC or Fox was a money-losing proposition instead of a highly profitable multi-billion dollar business."

The FCC's sports blackout rule was implemented in the mid-1970s to help shore up flagging attendance rates at games. But decades later, it's no longer clear that the NFL needs the assist, according to Wheeler. Last year, attendance rates were at 80 percent or higher for every stadium in the league. (Of course, this also means that most games were shown on TV.) And the popularity of football has never been higher on television. As The Atlantic's Derek Thompson pointed out recently, "nothing channels eyeballs like football."

On Tuesday, the FCC is expected to repeal the sports blackout rule over the objections of the NFL and its allies. Most votes at the agency these days are divided along partisan lines. But this time could be different — today, we're all sports fans.