Question: Morgan Carroll unsuccessfully ran against Mike Coffman for which of Colorado's congressional district?

Context paragraphs:
Gail Schwartz: Gail Sheridan Schwartz was a legislator in the U.S. state of Colorado.  Elected to the Colorado State Senate as a Democrat in 2006, Schwartz represented Senate District 5, which covers a large section of south-central Colorado, ranging from Aspen, and Delta, Colorado through the San Luis Valley to the New Mexico border.  Schwartz left office in 2015 after serving two terms and unsuccessfully ran for the United States House of Representatives in Colorado's 3rd congressional district.

Richard Allen (Texas politician): Richard Allen (June 10, 1830 – May 16, 1909) was a carpenter, contractor, businessman, and African-American Republican politician who was elected to two terms in the Texas House of Representatives.  Born into slavery in Richmond, Virginia, in 1830, he was brought to Texas in 1837.  While a slave he built a reputation as a skilled carpenter.  After emancipation, he became a contractor.  He built the mansion for Mayor Joseph R. Morris of Houston as well as the first bridge across Buffalo Bayou.  He became active in Republican politics and was elected to the Twelfth Legislature in 1869.  He unsuccessfully ran for the United States House of Representatives in 1870.  He was re-elected to the Thirteenth Legislature, but the election was contested, and his Democratic opponent, Gustave Cook, was seated in his place.  He unsuccessfully ran for lieutenant governor in 1878, the first member of his race to seek statewide office in Texas.  He remained active in the Republican party, and attended state and national conventions until 1896.  Allen also served as a quartermaster in the Texas militia and as a customs officer in Houston.  He was active in his church and in local community organizations.  He was married and had five children.  Upon his death in 1909, he was interred at the Olivewood Cemetery in Houston.

Colorado Democratic Party: The Colorado Democratic Party is the affiliate of the Democratic Party in the U.S. state of Colorado.  Its Chair is Morgan Carroll.

Mike Coffman: Michael Howard Coffman (born March 19, 1955) is the U.S. Representative for Colorado 's 6 congressional district , serving since 2009.  A member of the Republican Party, he previously served as the Secretary of State of Colorado (2007–2009) and as Colorado State Treasurer (1999–2005 and 2006–2007).

Morgan Carroll: Morgan Lenore Carroll (born November 24, 1971) is an American politician from Colorado and is currently the Chairwoman of the Colorado Democratic Party.  A Democrat, Carroll represented Colorado House District 36 in the city of Aurora from 2004 to 2008, and she represented the state's 29th Senate district from 2009 to 2017.  Carroll served as President of the Colorado State Senate from 2013 to 2014 and as minority leader in 2015.  Carroll stepped down as minority leader in July 2015 to unsuccessfully run against incumbent Republican Mike Coffman for Colorado's 6th congressional district in the U.S. House of Representatives.  In addition to her legislative work, Carroll works for the law firm of Bachus & Schanker.

E. J. Pipkin: Edward Joseph Pipkin, Jr. (born November 1, 1956) is a Republican a former member of the Maryland State Senate, had represented Maryland's 36th Senate district, and was first elected in 2002 and served until 2013.  Prior to his election to the state senate, he worked in the field of business finance, trading bonds in New York City.  He also founded an environmental group known as "Citizens Against Bay Dumping," during which he was successful in lobbying for legislation that banned irresponsible disposal of dredge spoils in the Chesapeake Bay.  Pipkin currently lives in Dallas.  In 2004, he unsuccessfully ran for the U.S. Senate against Barbara Mikulski.  Then, in 2008, he unsuccessfully ran for Congress in Maryland's 1st congressional district, against incumbent Wayne Gilchrest and State Senator Andy Harris, losing the primary to Andy Harris.  On August 5, 2013, Pipkin announced he would retire from the State Senate to attend graduate school.

Craig Romero: Craig Francis Romero (born September 25, 1954) is a New Iberia corporate salesman who represented District 22 in the Louisiana State Senate from 1993 to 2008.  The district includes the parishes of Iberia, Lafayette, St. Martin, and Vermilion.  Romero was president of the Iberia Parish government from 1984 to 1992.  He unsuccessfully ran as a Republican for the U.S. House of Representatives in Louisiana's Third Congressional District in both 2004 and 2006.

Bernie Buescher: Bernie Buescher (born July 11, 1949) is the former secretary of state of Colorado.  A Democrat, he was appointed to the office in 2009 by Governor of Colorado Bill Ritter to fill the vacancy left by the resignation of Republican Mike Coffman.

John MacGovern: John F. MacGovern (born July 14, 1951) is an American politician who represented the 2nd Middlesex District in the Massachusetts House of Representatives from 1983-91.  He was the Republican nominee in the Massachusetts's 5th congressional district election in 1990, losing to incumbent Chester G. Atkins 52% to 48%.  He later moved to Vermont.  He was an unsuccessful candidate for the Vermont Senate in 2004 and 2006.  He unsuccessfully ran as the Republican nominee for the United States Senate seat held by Bernie Sanders in the 2012 election.

Parker Griffith: Rolf Parker Griffith, Jr. (born August 6, 1942) is an American retired radiation oncology physician, mathematics teacher, Army Reserve officer, entrepreneur and politician who served in the Alabama State Senate from 2006 to 2008 and then as the U.S. Representative for  's 5 congressional district from 2009 to 2011.  A lifelong member of the Democratic Party, while serving in Congress, at the urging of Republicans he switched parties on December 22, 2009.  He ran for re-election in 2010 but was defeated in the Republican primary by Mo Brooks.  He returned to the Democratic Party in 2014 and unsuccessfully ran for Governor of Alabama in the 2014 election.

Supporting paragraphs: Morgan Carroll Mike Coffman
Answer: Colorado's 6th congressional district