Republican Sen. Tom Cotton of Arkansas won't be running for president in 2024, a source close to Cotton confirmed to CBS News on Sunday.  Cotton has been calling donors and friends to inform them of his plans to not run. Politico first reported the news. Cotton, who was first elected to the Senate in 2014, is one of the Republican party's rising stars. He has pushed a "tough on crime" agenda, including saying on "CBS Mornings" last week that "we need to crack down" following the attack on Paul Pelosi, the husband of House Speaker Nancy Pelosi. "The answer to all of these crimes is to get tough on crime and throw the book at these criminals," Cotton said on "CBS Mornings." He added that "we should throw the book" at the assailant in the Pelosi attack.  Cotton, in a safe Republican seat, is not up for reelection this year. He was reelected in 2020 with more than 66% of the vote.  Since then, he has traveled around the country – including making stops in Iowa and New Hampshire, the two cr