Democratic Rep. John Delaney fended off a spirited and well-funded Republican challenge on Tuesday to win a third term in Congress from Maryland's 6th District.
The centrist Democrat and former banker beat Amie Hoeber, who was a deputy undersecretary of the Army in the Reagan administration.
At a victory party in Gaithersburg, Delaney said voters want clear-eyed elected officials who can find practical solutions and work across the aisle.
"That should be our sacred trust," he said. "That's what I've tried to do as your member of Congress, and that's what I'm going to do going forward."
Delaney promised to work on transportation and for veterans.
The 6th District, which stretches from Montgomery and Frederick counties through Western Maryland, was by far the state's most competitive House contest in 2014. Delaney narrowly won reelection that year, besting Republican nominee Dan Bongino by less than 2 percentage points.
Sensing vulnerability, Republicans recruited Hoeber to challenge Delaney this year. She ran an aggressive campaign focused in part on Delaney's support for President Barack Obama's controversial Iran nuclear deal.
A super PAC funded by Hoeber's husband invested more than $3 million in advertising on her behalf.
Hoeber told supporters gathered in Frederick that the 16 months she spent campaigning were "amazing," and that the transportation plan she worked out with Republican Gov. Larry Hogan would have lasting effects in the district, if enacted.
Delaney, 53, is widely considered a potential Democratic candidate for governor in 2018. He has denied having any designs on the job.
He has antagonized Hogan on policy and political issues. He paid for a mobile billboard to circle the State House in March to challenge the governor to take a position on the candidacy of Donald Trump.
The 8th House District race also featured Libertarian David L. Howser and Green Party candidate George Gluck.
All eight of Maryland's House seats were on the ballot in Maryland Tuesday. The state's six incumbents — five Democrats and one Republican — all won reelection.
Baltimore Sun reporter Erin Cox and Mark Boyle and George Gerbo contributed to this article.