Question: Who did the founder of Coalition for Open Democracy unsuccessfully challenge for the US senate 
Context: Coalition for Open Democracy is a New Hampshire-based nonprofit devoted to campaign finance reform.  It was formed in 2009 by Doris "Granny D" Haddock. The Grêmio Recreativo Escola de Samba Império Serrano is a samba school of the city of Rio de Janeiro, that was created on March 23 of 1947 after a disagreement of the extinct samba school Prazer da Serrinha.  It was nine times champion of the Carnaval and can be considered one of the most traditional schools of the samba of the city.  One of the principal vainglories of its members is the open democracy of the school, established in the school's foundation.  Its history is normally confused with the history of the Morro da Serrinha, despite its headquarters being in Avenida Ministro Edgard Romero near the Estação Mercadão de Madureira, but in the same neighborhood: Madureira. Mikhail Suprun "Михаил Николаевич Супрун" (born 5 April 1955 in Severodvinsk) is a Russian historian and professor of the Pomor State University named after M. V. Lomonosov.  In 2009 he was arrested in connection with a book he wrote on what Open Democracy has called a "trumped up charge". Doris "Granny D" Haddock (January 24, 1910 – March 9, 2010) was an American political activist from New Hampshire.  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.  In 2004, she ran unsuccessfully as a Democratic challenger to incumbent Republican Judd Gregg for the U.S. Senate. Charles Andrew Jonas (August 14, 1876 – May 25, 1955) was an American attorney and politician, serving one term as a U.S. Representative from western North Carolina from 1929 to 1931.  A Republican, he was appointed as United States Attorney for the western district of North Carolina, serving from April 1, 1931, to July 1, 1932.  Jonas later unsuccessfully ran for the US Senate and House of Representatives. Vernon Jones (born October 31, 1960) is an African-American Democratic politician from the US state of Georgia.  Jones was chief executive officer of Dekalb County, Georgia, from 2001 until 2009, and in the Georgia House of Representatives from 1993 to 2001.  As Dekalb County CEO, Jones presided over the Board of Commissioners, oversaw a 7,000 employee county workforce, and managed a $2.6 billion county operating budget.  He unsuccessfully ran for the US Senate in 2008.  After unsuccessful runs for the US House of Representatives (2010) and DeKalb County Sheriff (2014), Jones was elected to the Georgia House in 2016. Armistead Thomson Mason (August 4, 1787February 6, 1819), the son of Stevens Thomson Mason, was a U.S. Senator from Virginia from 1816 to 1817.  Mason was also the youngest person to ever serve in the US Senate at the age of 28 and 5 months even though the age of requirement for the US Senate in the constitution is 30 years old. John Morrison (born 1961) is an American politician who was the Montana State Auditor and Insurance and Securities Commissioner from 2001-2008, and currently an attorney, writer and businessman.  He was the founding president of the National Alliance of State Health CO-OPs (NASHCO), which includes all “Consumer Operated and Oriented Plans” authorized and funded under the Patient Protection and Affordable Care Act.  He is also co-founder and vice-chair of the Montana Health CO-OP, one of the first CO-OPs to be approved for funding by the U.S. Department of Health and Human Services.  Morrison is a senior partner at Morrison Sherwood Wilson Deola, a public interest law firm based in Helena, Montana.  In 2006 he ran unsuccessfully in the Montana Democratic primary for the US Senate nomination. Gar Alperovitz (born May 5, 1936) is an American political economist and historian.  He was the Lionel R. Bauman Professor of Political Economy at the University of Maryland, College Park Department of Government and Politics from 1999 to 2015.  Alperovitz was a Fellow of King's College, Cambridge; a founding Fellow of the Harvard Institute of Politics; a Fellow at the Institute for Policy Studies; and a Guest Scholar at the Brookings Institution.  He also served as a Legislative Director in the US House of Representatives and the US Senate and as a Special Assistant in the US Department of State.  Alperovitz is a member of the board of directors for the New Economics Institute and a founding principal of the Democracy Collaborative.  As of April 2015, he serves on the Green Shadow Cabinet of the United States as "New Economy Advisor to the President". Lillian Ford Feickert (July 20, 1877 – January 21, 1945) was an American suffragette, New Jersey state political organizer, and the first woman from New Jersey to run for United States Senate.  She served as the President of the New Jersey Woman Suffrage Association from 1912 to 1920, and later helped organize the New Jersey League of Women Voters.  She went on to serve as the Vice-Chairman of the New Jersey Republican State Committee and unsuccessfully ran for the US Senate in 1928.
Answer: Judd Gregg