San Francisco ? A tearful Cindy Sheehan cited her son, killed in Iraq, as her inspiration as she announced her candidacy Thursday for the U.S. House against Rep. Nancy Pelosi.

Sheehan last month said she intended to run against Pelosi, the House speaker, if the San Francisco congresswoman didn’t move to impeach President Bush by July 23.

Nadeam Elshami, a spokes-man for Pelosi, would not comment on Sheehan’s candidacy but said the speaker has always opposed the war in Iraq and has focused on bringing troops home “safely and soon.”

After her 24-year-old son, Casey, was killed in Iraq in 2004, Sheehan gained international attention by setting up camp outside the president’s Texas ranch and demanding to meet with him.