Question: Did a Democrat or Republican win U.S. Senate in 2016?

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.

Ron DeSantis: Ronald Dion DeSantis (born September 14, 1978) is an American politician who has been the United States Representative for Florida 's 6 congressional district since 2013.  A member of the Republican Party, he ran in Florida's 2016 U.S. Senate election; however, DeSantis withdrew from the race following incumbent Senator Marco Rubio's announcement that he would seek reelection to the Senate, reversing his initial pledge not to run, on June 22, 2016.  After Rubio's decision to re-enter the U.S. Senate race, DeSantis opted to run for re-election to his U.S. House seat.

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.

Josh Mandel: Joshua A. Mandel (born September 27, 1977) is an American Republican politician who is the incumbent State Treasurer of Ohio.  Mandel has held elected office since 2003: as a city councilman, from 2003 to 2007; as a member of the Ohio House of Representatives, from 2007 to 2011; and as state treasurer since 2011.  He was the Republican challenger to incumbent Senator Sherrod Brown in the 2012 U.S. Senate election in Ohio, but was defeated.  In 2016, he announced his intention to again challenge Brown in the 2018 U.S. Senate election in Ohio.

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.

Neil Gorsuch Supreme Court nomination: After his nomination on January 31, 2017, Neil Gorsuch was confirmed by the Senate on April 7, 2017.  Gorsuch, age 49, is the youngest sitting Supreme Court justice since Clarence Thomas.  In February 2016, U.S. Supreme Court Associate Justice Antonin Scalia died, leaving a vacancy on the highest federal court in the United States.  Article II of the U.S. Constitution requires the president to nominate justices to the Supreme Court, subject to the "advice and consent" of the United States Senate.  President Barack Obama, a Democrat, nominated Merrick Garland to fill the vacancy.  U.S. Senate majority leader Mitch McConnell, a Republican, arguing that the presidential election cycle having already commenced made the appointment of the next justice a political issue to be decided by voters, refused to bring the Garland nomination to the Senate floor for a vote.  McConnell's action held the Supreme Court vacancy open through the end of President Obama's tenure.

United States Senate election in Louisiana, 1996: The 1996 Louisiana United States Senate election was held on November 5, 1996 to select a new U.S. Senator from the state of Louisiana to replace retiring John Bennett Johnston, Jr. of Shreveport.  After the jungle primary election, state treasurer Mary Landrieu went into a runoff election with State Representative Woody Jenkins of Baton Rouge, a former Democrat who had turned Republican two years earlier.  She prevailed by 5,788 votes out of 1.7 million cast, the narrowest national result of the thirty-three races for the U.S. Senate that year and one of the closest election margins in Louisiana history.  At the same time, Democrat Bill Clinton carried Louisiana by a considerable margin of 927,837 votes to 712,586 cast for Republican Bob Dole.

Tom Campbell (California politician): Thomas John Campbell (born August 14, 1952) is an American academic, educator and former politician.  He is Professor of Law at the Dale E. Fowler School of Law, and a Professor of Economics at the George Argyros School of Business and Economics, at Chapman University, in Orange, California.  He was Dean of Chapman University School of Law from 2011-16, a former five-term Republican United States Congressman from California's 12th and 15th districts, former member of the California State Senate, a former professor at Stanford Law School, former dean of the Haas School of Business, and former professor of business administration at the University of California, Berkeley.  In 2000 he retired from his House seat to run for the U.S. Senate but lost decisively to incumbent Dianne Feinstein.  He served as the Director of Finance for the State of California from 2004 to 2005.  On June 8, 2010, he lost his third bid for the United States Senate, and second for the seat held by Democrat Barbara Boxer, losing the Republican nomination to Carly Fiorina.

Daniel J. Jones: Daniel J. Jones is President of the Penn Quarter Group, a research investigative advisory based in Washington, D.C.  He previously worked as a researcher and investigator for the U.S. Senate and the U.S. Federal Bureau of Investigation (FBI).  As a staff member of the U.S. Senate Select Committee on Intelligence, he led several prominent investigations, including the largest investigative review in U.S. Senate history, The Committee Study of the Central Intelligence Agency's Detention and Interrogation Program (aka, the Senate Torture Report).  The investigation, which was based on more than 6.3 million pages of classified documents, was described by the "Los Angeles Times" as the "most extensive review of U.S. intelligence-gathering tactics in generations..." Jones was the subject of a three-part series in "The Guardian" in September 2016.

J. James Exon: John James "Jim" Exon (August 9, 1921June 10, 2005) was an American Democratic politician.  He served as the 33rd Governor of Nebraska from 1971 to 1979, and as a U.S. Senator from Nebraska from 1979 to 1997.  Exon was a Nebraska Democrat who never lost an election, and the only Democrat to hold Nebraska's Class 2 U.S. Senate seat.  He was elected and re-elected governor in 1970 and 1974, elected to the Senate in 1978, and re-elected in 1984 and 1990.  He is the only Nebraskan besides George Norris, the architect of Nebraska's unicameral legislature, to win five consecutive statewide elections.

Supporting paragraphs: Shirley Breeden Joe Heck
Answer: Democrat