Senator John Thune Says Deals Get Done in Senate Gym!!!

Senator John Thune revealed to our photog ... the only place on Capitol Hill where Democrats and Republicans can put aside their differences is in the Senate weight room.

We got the South Dakota Republican at Reagan National Airport Monday and he vouched for NY Senator Chuck Schumer, saying his tears were real because he's an emotional guy, even at the gym.

That opened the door to talking about the super exclusive Senate gym, and who knew this is where political enemies lay down their differences.

And if you believe him, the weights are mislabeled ... because in D.C. it's all about power!!!