Maryland became the seventh state to join the Union on April 28, 1788. Maryland’s first two senators, Charles Carroll and John Henry, took office on March 4, 1789. Maryland’s longest-serving senators include Millard Tydings (1927-1951), Paul Sarbanes (1977-2007), and Barbara Mikulski (1987-2017). In 2011 Barbara Mikulski became the longest-serving female senator to date. Mukulski was also the first Democratic woman to serve in a leadership position, as Democratic Conference secretary. John Howard and Samuel Smith both served as the Senate’s president pro tempore. As vice president, Spiro Agnew was the Senate’s constitutional president or presiding officer.

Two-term Democrat Ben Cardin was re-elected with 56% of the vote in 2012. He won the Democratic primary. Tony Campbell, Evan Cronhardt, Nnabu Eze, Gerald Smith, and Blaine Taylor were seeking the Republican nomination, with Campbell winning. Arvin Vohra, vice chairman of the Libertarian National Committee, sought the Libertarian Party nomination. Independents Neal Simon and Edward Shlikas[citation needed], and Michael B Puskar ran. Cardin won re-election to a third term in office.