Question: Who did the founder of Coalition for Open Democracy unsuccessfully challenge for the US senate 
Sentence (from "Doris Haddock"): Haddock achieved national fame when, between the ages of 88 and 90, starting on January 1, 1999, and culminating on February 29, 2000, she walked over 3200 mi across the continental United States to advocate for campaign finance reform.
Relevant evidence: No