United States Senator and former Republican presidential candidate Marco Rubio is demanding answers about a Fort Drum soldier who promoted a pro-communist message while in uniform.

Rubio (R - Fla.) sent a letter to Army Secretary Ryan McCarthy about Second Lieutenant Spenser Rapone. Recent photos on Rapone's social media accounts show him wearing a Che Guevara tee shirt under his military uniform, and holding a cap with a message inside reading "communism will win."

Fort Drum officials are looking into the issue, saying Rapone deserves a fair chance instead of a "knee-jerk reaction." But Rubio calls his actions an extreme embarrassment for the Army. He's asking how Rapone was able to obtain a commission, and is calling for it to be nullified.

Rubio is asking for a response in the next 30 days.