Mexico Is America's Team
The United States has hosted the last seven CONCACAF Gold Cups, which you'd believe would provide the USMNT with a significant home field advantage. However, attendance figures make it clear that Mexico has the most loyal support in the States.
In the six Gold Cups dating back to 2005 (not including this year's tournament), Mexico has always drawn more fans to its matches than the USMNT. Although Mexico doesn't play as often in the U.S. as the USMNT, the differences are significant and suggest that El Tri has more dedicated fans in their rival's home turf.