When ranking sports Americans love to watch either in person or on TV, it goes something like this:
College Basketball (in March anyway)
Major Golf Tournaments (Masters, US Open, etc.)
After that, you might argue that even major tennis tournaments draw more eyeballs in the U.S. than most soccer events...at least from Americans. And I didn't even mention WWE.
Sure, you put a pair of Premier League teams or squads from La Liga in stadiums here and people will show up, but many of them will be from the countries where those teams play rather than from the States. Why is that, exactly? Soccer is extremely popular among kids across the country. There are even adults with leagues. But, it just doesn't translate into butts in seats at stadiums or eyes glued to TVs.
Some might also say the pace of play in soccer costs them. How can you have a sport where the match can end in a nil-nil tie? But, there are plenty of people who love pitchers duels and low-scoring football in the snow. Millions crowd around TVs to watch people swim fast in a straight line during the Olympics.
Part of the reason may be that soccer is not native to our country. Kids here grow up with baseball, football and basketball as American past times. They play soccer, but they don't watch it, at least not to the degree they watch the other major sports owed heavily to the fact that those sports get prime spots on networks because of their popularity. As beloved as fútbol may be across the globe, it's lack of roots here in the U.S. certainly contribute (perhaps selfishly on our part) to our lack of watching interest even as kids and teens line up in huge numbers to participate.
Then there is the fact that we are loaded down with popular spectator sports, all of which know exactly how to market themselves to fans. They understand their audiences on a deep level and that translates into huge advertising dollars and massive television contracts.
Most importantly, we aren't very good at the sport. There are no signature stars who play here or anywhere else for that matter. The best players in the sport are from other parts of the world and most of them choose to play in leagues closer to home both for the competition and the money. In much the same way you rarely see a great football star from outside the U.S., soccer has a dearth of great American players. The U.S. men's team couldn't even qualify for the World Cup.
Which brings us to the fact that our best soccer players are women, but women's sports fall well behind men when it comes to people who watch them. That list above, note that it does not include a single women's sport, except tennis, where women are the more popular gender. As antiquated as it may be, fans prefer to watch men's sports far and away above women's. As a result, having a great soccer team populated by fierce women players is barely a blip on the sports radar.
So, the answer to whether or not soccer will ever make a dent in the American sports consciousness to such a degree that it would rank with its professional counterparts in popularity is: probably not. Things change, of course. Boxing used to be perhaps the biggest sport in America at one time. But, it will take a lot of things changing for America to embrace soccer the way it does football, baseball or basketball, which is unfortunate.