In 1923, Mae Ella Nolan, a Republican from San Francisco, became the first woman in the nation to succeed her husband who died while serving in Congress.  Since then, three-dozen other women have either been elected or appointed to the House of Representatives after their husbands died. 

Debbie Walsh is with the Center for American Women and Politics at Rutgers University. She says widows may ride into office on sympathy and name recognition, but they become just another lawmaker when seeking a second term.

"Once you're an incumbent you certainly do have an advantage, but I think that they do have to prove themselves and be seen as competent and viable candidates."

Walsh says 15 so called "political widows" have ended up holding office for two or more terms.

If elected, Doris Matsui would join two other congresswomen from California who filled the seats of their late husbands -- Democrat Lois Capps of Santa Barbara and Republican Mary Bono of Palm Springs.