HILLARY CLINTON and Donald Trump blame each other for plenty of things. But there's something many think they may both be to blame for: the decline in the NFL's television ratings.

By the league's own research, ratings were down 13.4% this season compared to 2015 through the first four weeks, and a popular theory ties the dramatic drop to the craziness of the campaign. (By comparison, ratings fell 3.8% from 2011 to '12.) On Sept. 26, the first presidential debate drew 84 million viewers, far outpacing the 8.1 million who watched Falcons vs. Saints, the lowest reported total in the 47 seasons of Monday Night Football. Similarly, this week's Giants-Packers game on Sunday Night Football drew 16.6 million on NBC when it went up against the second Clinton-Trump showdown (66.5 million viewers), down almost 25% from the same time last year.

Each of the league's three primetime showcases had experienced a double-digit percentage drop in viewers. Overall, Fox and CBS were down 3%, NBC was down 13% and ESPN was down 17%. Politics isn't the only reason for the plunge. The league also may have been hurt this year by a number of factors: an awful set of prime-time games; a smaller group of star quarterbacks (the retired Peyton Manning, the injured Tony Romo and the suspended Tom Brady were all missing); the Colin Kaepernick controversy; cord-cutting; and a public that has an increasingly better understanding of football's dangerous health effects.

There's also this: Nothing goes up forever, and the NFL was due for a ratings correction.

The big tell will be how the NFL does from the end of the election season, in November, to the end of the regular season. If the ratings are flat or tick up versus 2015's, you'll know the Presidential election campaign had a lot to do with it.