Progressive activist and organizer Alison Hartson
CNN  — 

Progressive activist and organizer Alison Hartson announced Thursday she is joining the race to challenge Democratic California Sen. Dianne Feinstein.

Hartson made it official during an appearance on “The Young Turks” online news show. She enters the state’s increasingly crowded open primary contest with the backing of The Young Turks host and founder Cenk Uygur, his progressive media network and a political group he co-founded, the Justice Democrats.

“California needs a bold progressive to lead the way and this particular race, in 2018, is going to be one of the most if not the most important race, in 2018, in the country and that’s because California has the sixth largest economy in the world and what we do does, in fact, influence the country,” Hartson said during an interview with Uygur, who announced he will act as a campaign adviser.

“We’re coming – we’re coming at 100 miles an hour,” Uygur said. “This will not be a normal campaign … when you find out how conservative Dianne Feinstein is, it is unconscionable that she is our senator in California.”

Uygur’s co-host, Ana Kasparian, considered running under the same banner, but ultimately opted against it, setting off a weeks-long internal search for a candidate. Hartson has ties of her own to Uygur, having worked as national director of Wolf PAC, a grassroots group he unveiled at the Occupy Wall Street encampment in October 2011.

The slate of progressive challengers to Feinstein, 84, is headed up by Kevin de León, the state Senate president, who formally joined the fray last month. De León’s work to advance a statewide single-payer health care bill earned him political capital with California’s robust Democratic left.

Feinstein, meanwhile, has been attacked by many of the same groups for being insufficiently critical of Trump and a centrist outlier in an increasingly liberal state.

Billionaire Tom Steyer, seen most recently in ads pushing for the impeachment of President Donald Trump, is also mulling a run. Activist investor Joe Sanberg, a champion of the earned income tax credit, could still join the race.

The state’s open primary is slated for June 5, 2018. The top two two overall vote-getters, regardless of party, will advance to the general election in November. Feinstein is expected to survive the first round. The race now will focus on the growing slate of challengers, each vying for the support of the party’s progressive wing.