99% sure the guy on the right is Vice President John Nance "Cactus Jack" Garner. At the time of the photograph he would have been President of the Senate. He was Vice President during part of the Roosevelt Administration and one of the last people that John F Kennedy talked to before his tragic death in Dallas in 1963. Kennedy had called Garner and had wished him a happy 95th birthday a few hours before the flight to Dallas.
Garner had a saying about the vice presidency that is not too family friendly so it wouldn't be appropriate for this forum. Garner pretty much told people what he thought of things. He died in Uvalde, Tx at the age of 99 in 1967.