Question: Shirley Breeden narrowly beat which Republican for the 2008 term Nevada United States Senate seat?

Context paragraphs:
Joe Heck: Joseph John “Joe” Heck (born October 30, 1961) is an American politician, physician, and U.S. Army Brigadier General who had served as the U.S. Representative for Nevada's 3rd congressional district from 2011 to 2017.  Heck, a member of the Republican Party, is a board-certified physician and served as a Nevada State Senator from 2004-08.  He ran unsuccessfully against Democrat Catherine Cortez Masto in the general election for the open Nevada United States Senate seat in 2016.  In the same year, Heck made headlines by joining a long list of Republicans who opposed the GOP nominee for President, Donald Trump.

United States Senate election in Delaware, 1972: The United States Senate election in Delaware, 1972 was held November 7, 1972.  Incumbent Republican United States Senator J. Caleb Boggs ran for a third term in the United States Senate.  Boggs faced off against Joe Biden, a New Castle County Councilman.  Though Senator Boggs was expected to easily win a third term over the then-unknown Biden, it ended up being the closest Senate election in 1972, and Biden narrowly beat out Boggs by a little over three thousand votes, winning what would be his first of seven terms.

Ohio gubernatorial election, 1822: The 1822 Ohio gubernatorial election was held on October 8, 1822.  Incumbent Democratic Governor of Ohio William Medill became governor after the resignation of Reuben Wood to accept a Senate seat, leaving Speaker of the Senate Allen Trimble to act as governor.  Former Senator, and 1820 gubernatorial challenger Jeremiah Morrow narrowly beat Trimble and former Ohio Supreme Court Justice William Irvin.

United States Senate election in Indiana, 2010: The 2010 United States Senate election in Indiana took place on November 2, 2010, alongside 33 other elections to the United States Senate in other states and elections to the United States House of Representatives and various state and local elections to fill Indiana's class III United States Senate seat.  Incumbent Democratic U.S. Senator Evan Bayh decided in February 2010 to retire instead of seeking a third term shortly after former U.S. Senator Dan Coats announced his candidacy for Bayh's contested seat.  No Democratic candidate submitted enough signatures by the deadline to run, leading Democratic officials to choose U.S. Congressman Brad Ellsworth to be the nominee.  The Libertarian Party nominated YMCA instructor Rebecca Sink-Burris, who had previously run against Evan Bayh in the United States Senate election in Indiana, 1998 but with less success than in this election.  Republican nominee and former U.S. Senator Dan Coats won the open seat.

United States Senate election in Nevada, 2012: The 2012 United States Senate election in Nevada was held on Tuesday, November 6, 2012, alongside 33 other elections to the United States Senate in other states, as well as elections to the United States House of Representatives, and the 2012 United States presidential election.  The primary election was held June 12, 2012.  Incumbent Republican U.S. Senator Dean Heller, who was recently appointed to this seat left vacant by resigning U.S. Senator John Ensign, was narrowly elected to his first full term over Congresswoman Shelley Berkley.

United States Senate election in Missouri, 2006: The 2006 United States Senate election in Missouri was held on November 7, 2006, to decide who would serve as senator for Missouri between January 3, 2007, and January 3, 2013.  The incumbent was Republican Jim Talent.  Talent was elected in a special election in 2002 when he narrowly defeated incumbent Democrat Jean Carnahan.  Carnahan had been appointed to the Senate seat following the posthumous election of her husband Mel Carnahan, who had died in a plane crash shortly before the 2000 election.  Talent's Democratic opponent was Missouri State Auditor Claire McCaskill.  Early on the morning of November 8, Talent conceded defeat to McCaskill, having faced considerable political headwinds.  Talent lost the election with 47% of the vote, to 50% of the vote for McCaskill.

Shirley Breeden: Shirley Breeden is a Democratic member of the Nevada Senate, representing Clark County District 5 (map) since 2009.  She won her first term in 2008, when she narrowly upset incumbent Republican Joe Heck.

United States Senate election in Tennessee, 2006: The 2006 United States Senate election in Tennessee was held on November 7, 2006.  The election winner, Bob Corker, served his term between January 3, 2007 and January 3, 2013.  Corker replaced Republican Bill Frist in the Senate, who retired upon the end of his second term in 2007.  Corker was the Republican nominee, and the Democratic nominee was Harold Ford, Jr..  The race between Ford and Corker was one of the most competitive Senate races of 2006, with Corker winning the race by less than three percent of the vote.  Corker was the only non-incumbent Republican to win a U.S. Senate seat in 2006.  Since 1994, the Republican Party has held both of Tennessee's Senate seats.

Duane Sand: Duane Sand (born May 8, 1965) is a North Dakota politician, a graduate of the United States Naval Academy, and was a U.S. Navy officer during the Iraq War.  Sand ran for the United States Senate in North Dakota on the Republican ticket in 2000 against incumbent Kent Conrad of the Democratic-Nonpartisan League, and was called for duty after the election in 2001.  Upon returning, he ran for North Dakota's lone House seat in 2004 and 2008, but failed both times to defeat incumbent Earl Pomeroy.  In August 2011, Sand announced his bid to become the 2012 Republican nominee for the same Senate seat he ran for 11 years prior.  He lost the Republican nomination to Representative Rick Berg.  Sand previously served as the North and South Dakota Director for Americans for Prosperity, a conservative political advocacy group.

United States Senate election in New Jersey, 2006: The 2006 United States Senate election in New Jersey was held on November 7, 2006.  Incumbent Democratic U.S. Senator Bob Menendez was elected to represent New Jersey in the United States Senate for a six-year term which ended in January 2013.  The seat was previously held by Democratic Governor of New Jersey Jon Corzine.  After he stepped down from his Senate seat and was sworn in Governor, Corzine appointed Rep. Menendez, who was sworn in on January 18, 2006.  Menendez was challenged by Republican Thomas Kean, Jr. and seven other candidates.  Filing for the primary closed on April 10, 2006.  The primary election was held on June 6, 2006.  Menendez became the first Hispanic to hold a U.S. Senate seat from New Jersey, and was the first Latino elected to statewide office in the state.

Supporting paragraphs: Shirley Breeden Joe Heck
Answer: Joe Heck