Indystar.com reports:

U.S. Sen. Dan Coats has decided not to run for reelection. “It has a lot to do with age,” he said in a phone conversation today. “If I served again and won I would be four months shy of 80 at the end of the term.” “You reach a time,” he said, “ when you have to acknowledge that it is time to step aside. And when you realize you have a responsibility to turn things over to the next generation. We have a deep bench and there probably hasn’t been a better time to do this.” Coats, a former U.S. House member and aide to then-Rep. Dan Quayle, retired from the Senate in 1999 and spent the next decade-plus working as a lobbyist and serving as the United State ambassador to Germany. In 2010, he surprised the state’s political establishment by announcing he would seek a return to the Senate. At the time, he was expected to face incumbent Democratic Sen. Evan Bayh in the November election.