With her support, both Democratic members of the New Hampshire congressional delegation are now backing Obama. Rep. Paul Hodes (D-N.H.) endorsed him in July.
Shea-Porter won a surprising upset last year, defeating former Republican Rep. Jeb Bradley with little help from the national and state Democratic establishment.
She has refused to accept financial and logistical assistance from the Democratic Congressional Campaign Committee’s Frontline program.
She is endorsed for reelection by EMILY’s List, which is also backing Obama’s leading rival, Sen. Hillary Rodham Clinton (D-N.Y.).