Sen. Tom Cotton, R-Ark. poses for photographers in his office on Capitol Hill in Washington, Wednesday, March 11, 2015. The rookie Republican senator leading the effort to torpedo an agreement with Iran is an Army veteran with a Harvard law degree who has a full record of tough rhetoric against President Barack Obama's foreign policy.
Sen. Tom Cotton, R-Ark. poses for photographers in his office on Capitol Hill in Washington, Wednesday, March 11, 2015. The rookie Republican senator leading the effort to torpedo an agreement with Iran is an Army veteran with a Harvard law degree who has a full record of tough rhetoric against President Barack Obama's foreign policy. AP
Sen. Tom Cotton, R-Ark. poses for photographers in his office on Capitol Hill in Washington, Wednesday, March 11, 2015. The rookie Republican senator leading the effort to torpedo an agreement with Iran is an Army veteran with a Harvard law degree who has a full record of tough rhetoric against President Barack Obama's foreign policy. AP