Pretty big, people actually follow and watch the World Cup.
One of the main issues is that the MLS sucks donkey dick, and that big time La Liga and Premiere league games come on so early here when everyone is at work.
Used to be an Irish Pub near my house, I remember that was the first time I really got introduced to how big soccer was overseas.
A lot of the guys from Ireland/England/Wales all went there, it was a smaller pub but it had great food. My buddy from Wales worked there, and he would sneak us pints (this is like 8th grade), he ended up passing away in a car wreck a few years back, cool guy.
Also the first time I was introduced to the fact that cunt is apparently ok to say. Went there one day for some games on a Saturday and I knew nothing about football, all the guys already drunk yelling "F'kn cunt" at the TV and it's not even lunch time yet, lmao.