Former Colorado state Sen. Mike Johnston, the architect of Colorado’s teacher effectiveness law and a leading Democrat in other past education reform efforts, is entering the fray in his party’s attempt to unseat Republican U.S. Sen. Cory Gardner.

Johnston, 44, will run in the Democratic primary in the 2020 election, The Denver Post reported Thursday.

“I think one of the things that gives me a real advantage is people are looking for someone who represents Colorado,” Johnston told the newspaper. “I’m a fluent Spanish speaker, and I’ve had a diverse set of experiences and jobs in all parts of Colorado.”

The Denver Democrat and Western Slope native ran unsuccessfully for governor last year, finishing third in the Democratic primary. Prominent supporters of education reform supported his campaign.

A former teacher and principal, Johnston was the author of Colorado’s  teacher effectiveness law, 2010’s Senate Bill 191. He also was a key figure in the passage of the READ Act, which created a new system to identify students in kindergarten through third grade with reading disabilities. He found bipartisan support to pass the ASSET bill, which provided in-state tuition for students who were born in another country.

Gardner is seen as vulnerable given the current political climate and Colorado’s increasingly blue hue. Democrats swept to power in elections for statewide offices in November.

So far, Johnston is the biggest-name Democrat to announce he wants to take on Gardner. Johnston also was early in announcing his run for governor.