Barbara Mikulski easily held off a challenge by state Sen. E.J. Pipkin to win a fourth term in the U.S. Senate.
With 91 percent of Maryland's precincts reporting, Mikulski led with 64 percent of the vote to 34 percent for Pipkin.
Her Republican challenger had hoped to repeat his upset defeat of an established Democrat. Pipkin, who resides in Queen Anne's County, snatched his Eastern Shore Senate seat from longtime Sen. Walter Baker in 2002.
Even as he conceded Tuesday night, he promised well-wishers in Annapolis that he would run another day.
"I promise you'll see me on the campaign trail again," Pipkin told supporters gathered at the state GOP election-night party.
Pipkin, 49, had established himself politically as a champion of the environment when in the late 1990s he led a successful effort to stop dredge spoil dumping near the Chesapeake Bay. He ran an aggressive campaign against Mikulski, 68, attacking her record on everything from defense to the environment.