Del. Michael Futrell (D-Prince William) plans to give up his seat in the House of Delegates to run for the state Senate district represented by retiring state Sen. Chuck Colgan (D-Prince William) next year.

He joins Atif Qarni and Jeremy McPike in the primary for a seat that has not been open in 30 years.

In an e-mail to supporters, Futrell cited the possibility of Medicaid expansion as the impetus for his campaign.

Futrell, a pharmaceutical salesman and founder of a nonprofit organization, narrowly won his House seat just last year despite being massively outspent by his Republican rival and facing a controversy over his nonprofit’s failure to file tax returns.

Both his potential primary opponents can likewise tout strong 2013 performances in this politically unpredictable Washington exurb. Qarni, a middle school math teacher and former Marine, came within 500 votes of defeating Del. Robert Marshall (R-Prince William) last year. McPike lost by even an even narrower margin to Del. Scott Lingamfelter (R-Prince William).

No Republican candidate has yet announced a campaign.

Colgan, a moderate and the longest serving member of the Senate, faced a tough challenge in his last race. Party leaders concerned about an open race have three times convinced Colgan to run again.

Redistricting has since made the district more Democratic, and voters there have favored Democrats in the last Senate, gubernatorial, and presidential races. However, an off-year local election could be more of a challenge.