Question: David Brock is a political activist and author for what political party?
Context: Media Matters for America (MMfA) is a politically progressive media watchdog in the United States.  The organization has a stated mission of "comprehensively monitoring, analyzing, and correcting conservative misinformation in the U.S. media".  Set up as a tax-exempt, nonprofit organization, MMfA was founded in 2004 by journalist and political activist David Brock as a counterweight to the conservative Media Research Center.  It is known for its aggressive criticism of conservative journalists and media outlets, including its "War on Fox News." Shareblue, formerly known as Blue Nation Review, is an American left-wing news website owned by the journalist and political activist David Brock.  The website is headed by former Clinton staffer Peter Daou.  Shareblue is within a consortium of political groups in Democratic strategist David Brock’s network that will raise a roughly $40 million budget to oppose President Donald Trump's policies. The New Alliance Party (NAP) was an American political party formed in New York City in 1979.  Its immediate precursor was an umbrella organization known as the Labor Community Alliance for Change, whose member groups included the coalition of Grass Roots Women and the New York City Unemployed and Welfare Council.  All of these groups were associated with controversial psychologist and political activist Fred Newman, whose radical health care collective Centers for Change and Marxist International Workers Party were active in grassroots politics in New York City.  The NAP's first chairperson was then-South Bronx City Councilman Gilberto Gerena-Valentin, a veteran Puerto Rican political activist.  .  The party is notable for getting African American psychologist Lenora Fulani on the ballot in all 50 states during her first Presidential campaign in 1988, making her both the first African-American and woman to do so. Manno (Emmanuel) Charlemagne, born 1948, is a Haitian political folk singer, songwriter and acoustic guitarist, lifelong political activist and former politician.  He recorded his political chansons in both French and in Creole.  He lived abroad in exile twice, both during the 1980s and again during the years 1991-1994, when the country was ruled by a military "junta" led by Raoul Cédras.  In 1995, Charlemagne was elected mayor of Port-au-Prince after running as an independent candidate, while Oganizadyon Politik Lavalas (OPL), J.B. Aristide's political party at the time, did not present a mayoral candidate for Port-au-Prince, many considered this decision by OPL as a sign that Aristide had supported Manno's candidacy.  He was mayor until 1999. David Brock (born November 2, 1962) is an American Neo-Liberal political operative, author, and commentator who founded the media watchdog group Media Matters for America.  He has been described by "Time" as "one of the most influential operatives in the Democratic Party". The Conservative Party, officially the Conservative and Unionist Party, is a centre-right political party in the United Kingdom.  It is currently the governing party, having been so since the 2010 general election, where a coalition government with the Liberal Democrats was formed.  In 2015, the Conservatives led by David Cameron won a surprise majority and formed the first Conservative majority government since 1992.  However, the 2017 snap election on Thursday 8 June resulted in a hung parliament, and the Conservatives lost their parliamentary majority.  They are reliant on the support of a Northern Irish political party, the Democratic Unionist Party (DUP), in order to command a majority in the House of Commons through a confidence-and-supply deal.  The party leader, Theresa May, has served as both Leader of the Conservative Party and Prime Minister since 13 July 2016.  It is the largest party in local government with 9,237 councillors.  The Conservative Party is one of the two major contemporary political parties in the United Kingdom, the other being its modern rival, the Labour Party.  The Conservative Party's platform involves support for free market capitalism, free enterprise, fiscal conservatism, a strong national defence, deregulation, and restrictions on trade unions. Balraj Madhok (25 February 1920 – 2 May 2016) was an Indian political activist and politician from Jammu.  Originally an activist of the Hindu nationalist organisation Rashtriya Swayamsevak Sangh (RSS), he later worked as a politician in the Bharatiya Jan Sangh (BJS).  Madhok was instrumental in launching the RSS in the princely state of Jammu and Kashmir and later the political party Jammu Praja Parishad for representing the interests of Jammu Hindus.  He eventually rose to become the president of the Bharatiya Jana Sangh and led its successful contest in the general election of 1967.  He resigned from the party afterwards due to political differences with Atal Bihari Vajpayee and L. K. Advani. The Republican Noise Machine: Right-Wing Media and How It Corrupts Democracy is a 2004 book written by David Brock which chronicles the author's opinion of how the American right wing was able to build its media infrastructure, and the tactics used by right-wing groups to pressure the media and spread misinformation to the public.  The book was the prelude to Brock's launching of his organization Media Matters for America. The Conservative Party of New Zealand is a fiscally and socially conservative political party in New Zealand.  It was founded in August 2011 by businessman and political activist Colin Craig, who led the party from its foundation until his resignation in June 2015.  Its current leader is Leighton Baker, since January 2017. The Australian Conservatives is an Australian political party formed and led by Cory Bernardi as a breakaway from the Liberal Party of Australia.  The party had been established as a conservative political activist group in July 2016, as response to the results of the 2016 federal election.  It was formed as a political party after Bernardi's resignation from the Liberals, following disagreements with the Liberal/National Coalition, its policies and leadership under Malcolm Turnbull.  The Family First Party and their two state incumbents Dennis Hood and Robert Brokenshire joined and merged in to the Australian Conservatives in April 2017.
Answer: He has been described by "Time" as "one of the most influential operatives in the Democratic Party".