Question: Heather Mizeur lost the 2014 election to what American lawyer and politician, who is currently serving as the U.S. Representative for Maryland's 4th congressional district

Context articles: Thomas Swann
Joe Kennedy III
Frederick R. Lehlbach
Donald McEachin
Heather Mizeur
Al Green (politician)
Anthony G. Brown
Steve Stockman
Blaine Luetkemeyer
Rico Oller

Thomas Swann (February 3, 1809 – July 24, 1883) was an American politician.
 Initially a Know-Nothing, and later a Democrat, he served as mayor of Baltimore (1856–1860), as the 33rd Governor of Maryland (1866–1869), and as U.S. Representative from Maryland's 3rd congressional district and then 4th congressional district (1869–1879).
Joseph Patrick "Joe" Kennedy III (born October 4, 1980) is an American lawyer and politician.
 He is currently serving as the U.S. Representative for Massachusetts 's 4 congressional district since 2013.
 He is a Democrat whose district extends from the western suburbs of Boston to the state's South Coast.
 A son of former U.S. Representative Joseph P. Kennedy II, he worked as a Peace Corps volunteer and as an assistant district attorney in the Cape and Islands and Middlesex offices before his election to Congress.
Frederick Reimold Lehlbach (January 31, 1876 – August 4, 1937) was an American lawyer and politician.
 As a Republican, Lehlbach served as the U.S. Representative for New Jersey's 10th congressional district from 1915 to 1933 and as the representative from New Jersey's 12th congressional district from 1933 to 1937.
 Lehlbach was also the nephew of Herman Lehlbach, a former U.S. Representative from New Jersey's 6th congressional district who served from 1885 to 1891.
Aston Donald McEachin (born October 10, 1961) is an American politician and lawyer who is the U.S. Representative from Virginia's 4th district.
 A Democrat, he served in the Virginia House of Delegates 1996–2002 and 2006–2008.
 From 2008 to 2017, he served in the Senate of Virginia, representing the 9th district, made up of Charles City County, plus parts of Henrico County and the city of Richmond.
 McEachin ran for Congress for the open seat of Virginia's 4th congressional district vacated by Republican Randy Forbes in 2016 and won the general election with 57.3% of the votes.
Heather R. Mizeur ( ; born December 6, 1972) is an American politician and member of the Democratic Party from the state of Maryland.
 She has served as a member of the Maryland House of Delegates from January 10, 2007 to January 14, 2015, representing the 20th district in Montgomery County.
 She was a candidate for Governor of Maryland in the 2014 election but lost the Democratic primary to Lieutenant Governor of Maryland Anthony G. Brown.
Al Green (born September 1, 1947) is an American lawyer, and politician who is currently serving as the U.S. Representative from Texas's 9th congressional district, serving since 2005.
 The district includes most of southwestern Houston, including most of that city's share of Fort Bend County.
 It also includes most of Missouri City.
 Green is a member of the Democratic Party.
Anthony Gregory Brown (born November 21, 1961) is an American lawyer and politician, who is currently serving as the U.S. Representative for Maryland's 4th congressional district.
 He previously served as the eighth Lieutenant Governor of Maryland, from 2007 to 2015.
 He was elected as lieutenant governor in 2006 on the Democratic ticket with Governor Martin O’Malley, and both were reelected in 2010.
 In 2014 he ran unsuccessfully for Governor of Maryland, losing to Larry Hogan.
 Brown previously served two four-year terms in the Maryland House of Delegates, representing Prince George's County.
 He is currently a Colonel in the United States Army Reserve, having served in the U.S. Army for nearly thirty years.
 While lieutenant governor, Brown was one of the two highest-ranking elected officials in the nation to have served a tour of duty in Iraq.
Stephen Ernest "Steve" Stockman (born November 14, 1956) is an American politician and member of the Republican Party.
 He served as the U.S. Representative for Texas's 9th congressional district from 1995 to 1997 and for Texas's 36th congressional district from 2013 to 2015.
 Stockman ran in the 2014 election for the United States Senate but lost the Republican primary to incumbent Senator John Cornyn.
William Blaine Luetkemeyer (born May 7, 1952) is an American politician currently serving as the incumbent U.S. Representative for Missouri 's 3 congressional district , a seat he has held since 2009.
 The district, numbered as the 9th Congressional District from 2009 to 2013, contains most of east-central Missouri, including the state capital of Jefferson City and some of the southern and northern St. Louis suburbs and exurbs.
 Luetkemeyer is a member of the Republican Party.
Thomas "Rico" Oller (born July 16, 1958) is a Republican U.S. politician from California.
 He served in the California State Assembly, representing the 4th District from 1996 to 2000, and the California State Senate, representing the 1st district from 2000 to 2004.
 In 2004, Oller ran for Congress in California's 3rd congressional district, but narrowly lost the Republican primary to former California Attorney General Dan Lungren.
 On January 10, 2008, Oller again ran for Congress, this time in California's 4th congressional district, for a seat being vacated by retiring Congressman John Doolittle.
 He faced opposition from former Congressman Doug Ose.
 On March 4, 2008, Oller dropped out of the race when California State Senator Tom McClintock (R-Thousand Oaks) announced that he was running for Doolittle's seat.
 In a statement, Oller said his decision was "a bitter pill indeed for me to swallow."
 But, he said he was endorsing McClintock to prevent the election of Ose, whom he labeled as "an unarguably liberal Republican."
 Oller ran for the newly former 5th Assembly District in 2012 facing Madera County Supervisor Frank Bigelow in the November general election.
 Oller lost to Bigelow by 5.7%.