FILE - In this Jan. 14, 2015 file photo, Outgoing Maryland Lt. Gov. Anthony Brown greets members of the House of Delegates in Annapolis, Md., the first day of the 2015 legislative session. Eighteen months after he surprisingly lost his bid for the state's highest office, a safely Democratic seat in Congress will be no easy consolation prize for Brown, who is locked in a tough three-way battle. (AP Photo/Patrick Semansky, File)
Former Secretary of State Hillary Rodham Clinton, right, campaigns for Maryland Democratic gubernatorial candidate, Lt. Gov. Anthony Brown, left, during a rally at the University of Maryland, Thursday, Oct. 30, 2014, in College Park, Md. (AP Photo/Patrick Semansky)
Democrat Anthony Brown, who is running against Republican Larry Hogan, has been lieutenant governor of the state under Gov. Martin O'Malley since 2007. Mr. Hogan has criticized that Mr. Brown will continue what he views as Mr. O'Malley's failed policies. (Associated Press)
Larry Hogan (right) the Republican candidate for Maryland governor, has made tax increases of the past eight years such a large issue in his campaign that he has forced Democrat Anthony Brown to promise no new taxes in the deep-blue state.
Maryland gubernatorial candidates Republican Larry Hogan, left, and Democrat Maryland Lt. Gov. Anthony Brown have a laugh before the Maryland gubernatorial debate at News Channel 8 in Arlington, Va., Monday, Oct. 13, 2014. Brown and Larry Hogan spent much of their second debate trading accusations and focusing on weaknesses. (AP Photo/The Washington Post, Melina Mara, Pool)
Maryland Democratic gubernatorial candidate, Lt. Gov. Anthony Brown, shakes hands with supporters outside a polling place at Hazelwood Elementary/Middle School on primary day in Baltimore on Tuesday, June 24, 2014. (AP Photo/Patrick Semansky) ** FILE **
Maryland Democratic gubernatorial candidates, Rep. Heather Mizeur, D-Montgomery, from left, Attorney General Doug Gansler and Lt. Gov. Anthony Brown embrace after participating in a Maryland Democratic primary gubernatorial debate at the University of Maryland in College Park, Md., Wednesday, May 7, 2014. (AP Photo/The Washington Post, Matt McClain, Pool)
Maryland Democratic gubernatorial candidates, Lt. Gov. Anthony Brown, center, Rep. Heather Mizeur D-Montgomery, in blue, and Attorney General Doug Gansler, back left, are introduced as panelist Chris Gordon, right, looks on prior to a Maryland Democratic primary gubernatorial debate at the University of Maryland in College Park, Md., Wednesday, May 7, 2014. (AP Photo/The Washington Post, Matt McClain, Pool)