Far from it. The fact that he's even won statewide office before proves that he has a lot of potential for the future. One loss won't end his entire career.
the guy only won statewide elections because they were races where the spotlight wasn't on him. With the spotlight on him, he chokes EVERY TIME. Conway's career is done like Disco.
He's moderate enough to beat any anti-Democrat streak. Obama dragged him down this year (and in 2010). Come 2017, when Obama is out of the White House, all bets are off.
Conway has fought 5 elections. The two times that Republicans didn't seriously challenge him (when he ran for Atty Gen in 2007 and 2011), he obviously won. The three competitive races he ran, for the House in 2002, for the Senate in 2010, and for Governor in 2015, he all lost. The 2010 election can be excused by climate and location. The other two just cannot (the House district he lost, by the way, was held by the Democrats in 2010 under the same lines he lost it under). There is more Democratic talent than just Jack Conway in Kentucky. He is finished.