Democrat Ron BarberRonald (Ron) Sylvester BarberPrinciples and actions mean more than Jeff Flake’s words Giffords to lawmakers avoiding town halls: 'Have some courage' Ten House seats Dems hope Trump will tilt MORE raised almost $550,000 in the first seven weeks of his campaign to finish the term of former Rep Gabrielle Giffords (D-Ariz.), his campaign announced Thursday.

Barber’s campaign said 3,293 individuals had pitched in since he announced in February his campaign for the special election.

"I believe that fundraising isn’t just about the bottom line — it’s about people investing in someone they know will stand up for their values,” Barber said in a statement.

The former district director for Giffords, Barber was shot twice in the January 2011 shooting spree that critically injured Giffords and led to her resignation one year later.

Barber is unopposed in the Democratic primary, but four Republicans are duking it out in the GOP primary, including Jesse Kelly, who came within 2 points of unseating Giffords in 2010 in a toss-up district.

Most of the Republican candidates have not yet released their fundraising figures, but sports broadcaster Dave Sitton announced he raised more than $250,000 during the same period.

Barber’s first goal is to win a June special election to finish the remainder of Giffords’s term. But Barber has also announced plans to seek a full term in the House that starts in 2013. Barber will compete in the fall in the regular election in a redrawn district that slightly improves chances for Democrats.

—This post was updated at 10:50 a.m.