Calling him “one of the most creative and thoughtful leaders on education” nationwide, former U.S. Sen. Gary Hart on Wednesday endorsed Democrat Mike Johnston to be Colorado’s next governor.

“Ahead of almost all those in his emerging generation of leaders, Mike has understood the linkage between high quality public education, and continuing education, and employment and economic opportunity,” Hart said in an endorsement letter released by Johnston’s campaign.

Johnston has proposed that the state pay for two years of college or mid-career job training for Coloradans.

A former state senator from Denver, Johnston is one of four Democrats running in a primary for the office held by term-limited Gov. John Hickenlooper, also a Democrat. Other Democrats in the race include U.S. Rep. Jared Polis, former State Treasurer Cary Kennedy and businessman and civic leader Noel Ginsburg. Lt. Gov. Donna Lynne said last week she is formally exploring whether to launch a campaign.

Hart, who served two terms in the Senate and ran for president twice, recalled that he sought public office “on the twin themes of new leadership, generational change, and new ideas, new approaches to address new realities.” With that in mind, he says Johnston fills the bill for Colorado.

“Mike steadfastly avoids the partisanship that is handcuffing political progress at the state and national level and will seek bipartisan innovation at every opportunity,” Hart writes. “These new and different times require a new and different leader like Mike Johnston in the governor’s office.”

Johnston, a friend of Hart’s for 15 years since he was his student in law school, returned the praise.

“Sen. Hart is one of our nation’s greatest statesmen and most thoughtful leaders, who has been called on by presidents to tackle challenges as diverse as creating a homeland security strategy for the U.S. and monitoring Irish peace. We will do all we can to build a Colorado worthy of your vision,” Johnston said in a statement.

Earlier this week, Johnston announced he’d won an endorsement from former Denver Mayor Wellington Webb and his wife, former state Rep. Wilma Webb.