Ron Barber, a former aide to Rep. Gabrielle Giffords (D-Ariz.), is off to a strong start in his campaign to fill the ex-Congresswoman’s seat.

In the reporting period that began Jan. 1 and ended March 28, the Democrat raised almost $550,000 and had nearly $465,000 in the bank.

Barber raised the large sum in less than two months with a big hand from a who’s who of Democratic interest groups and Members.

Those Democratic Members whose campaign committees and PACs donated to the Barber campaign include House Minority Leader Nancy Pelosi (Calif.), House Minority Whip Steny Hoyer (Md.), House Assistant Minority Leader James Clyburn (S.C.), Democratic National Committee Chairwoman Debbie Wasserman Schultz (Fla.) and Reps. Nita Lowey (N.Y.), Mike Michaud (Maine) Allyson Schwartz (Pa.), Henry Cuellar (Texas), Jared Polis (Colo.) and John Larson (Conn.).

Barber also reported contributions and in-kind donations from Giffords’ campaign account, which is expected because she and her husband have endorsed him.

The interest groups that sent checks to Barber include Planned Parenthood, several unions, NARAL Pro-Choice America and the Human Rights Campaign.

Barber is the presumptive Democratic nominee for the June 12 special election. The special primary is April 17.

On the GOP side, veterans Jesse Kelly and Martha McSally and state Sen. Frank Antenori have yet to file their reports.

College sports TV broadcaster Dave Sitton (R) raised $261,000 and had $132,000 in cash on hand.

Roll Call rates the Arizona special election as a Tossup.