(Reuters) - The owner of a restaurant popular with presidential hopefuls and a former police chief won major party nominating contests on Tuesday and will face off in November in a notoriously fickle congressional district in New Hampshire, seen as a key prize with control of Congress at stake.

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Former state legislator Chris Pappas, a member of the state’s executive council administrative body, won the Democratic race to succeed retiring Democrat Carol Shea-Porter in New Hampshire’s 1st Congressional District, which has flipped four times between the two major parties this decade, tending to reflect the national political winds.

The Republican nominee was Eddie Edwards, a former police chief who defeated state Senator Andy Sanborn. He was supported by President Donald Trump’s lawyer, Rudy Giuliani, and if elected, would be the first black congressman from the state.

Holding the district is crucial for Democrats as they seek to gain 23 seats to capture a majority in the U.S. House of Representatives and try to thwart Trump’s Republican agenda.

All 435 seats in the House, as well as one-third of the 100-member Senate, will be up for grabs in the Nov. 6 elections.

Pappas emerged from a crowded primary of 11 people, with his most notable competition coming from former Obama administration official and U.S. Marine Corps veteran Maura Sullivan.

Edwards, meanwhile, won on the Republican side in a race with six people competing.

Political oddsmaking firms say this race leans to the Democrats; shortly after Pappas was confirmed as the winner, the projection firm Cook Political Report shifted the race to “likely Democratic” from “lean Democratic.”

Voter dissatisfaction with Trump’s leadership has powered gains by Democrats in special elections at the federal and state level over the past 18 months. They are currently seen as modest favorites to retake the House.

Pappas was endorsed by three of the four members of the state’s all-female congressional delegation. He is co-owner of the Puritan Backroom, a Manchester restaurant well-known for presidential candidate visits ahead of the state’s first-in-the-nation nominating primary. Manchester, which is part of the district, is the largest city in the state.

SWING DISTRICT

The district has a history of voting for the presidential winner - and then going against the party that holds the White House in subsequent congressional elections. Former Presidents George W. Bush and Barack Obama won the district twice, while Trump carried it by 1 percentage point over Democrat Hillary Clinton in 2016.

Another notable candidate in the Democratic race was Levi Sanders, son of U.S. Senator Bernie Sanders of neighboring Vermont, who ran unsuccessfully for the 2016 Democratic presidential nomination. The Vermont lawmaker, despite endorsing dozens of candidates across the country, had not backed his son.

Sanders, who was criticized for not living in the district, had garnered only about 2 percent of the vote with about 50 percent of precincts counted.

Voters also picked former Democratic state Senator Molly Kelly to challenge popular incumbent Republican Governor Chris Sununu in November. Seven Republicans were competing to take on Congresswoman Ann Kuster in the state’s second congressional district, which Cook now rates as “solid Democratic.”

This week will set the final congressional match-ups ahead of the November general election, with Rhode Island set to vote on Wednesday. New York voters, who have already picked nominees for Congress, pick candidates on Thursday for governor and other state races.