DEMOCRATS have claimed victory in a crucial Pennsylvania seat that was won by US President Donald Trump in a landslide at the 2016 election

Democrat and Marine veteran Conor Lamb told his crowd that voters had directed him to “do your job” in Washington. “Mission accepted,” he declared.

Earlier, Republican Rick Saccone told his own supporters, “It’s not over yet, we’re going to fight all the way, all the way to the end, we’ll never give up.”

Mr Lamb told CNN overnight he hadn’t yet heard from Mr Saccone, but added, “I congratulate him on fighting hard the whole way.”

Regardless of the outcome — and a recount was possible — Mr Lamb’s showing in a district Mr Trump won by 20 points in the presidential race was sure to stoke anxiety among Republicans nationwide and renewed enthusiasm among Democrats.

Mr Lamb’s lead currently stands at 641 votes — out of more than 224,000 votes cast, according to unofficial results.

Election officials said there are about 200 absentee votes and an unknown number of provisional ballots still to be counted.

In a race this close, either candidate’s supporters can ask for a recount.

The ultimate winner will face re-election in just eight months, and the congressional district as currently shaped will likely vanish next year thanks to a court-ordered redrawing of the state’s district maps.

Yet Mr Trump and his chief allies invested tremendous time and resources in keeping the seat in Republican hands, mindful the contest could be used to measure Mr Trump’s lasting appeal among white, working-class voters and Democrats’ anti-Trump fervour.

The White House scrambled to rally voters behind Mr Saccone, who cast himself as the president’s “wingman,” but he struggled at times to connect with the blue-collar coalition that fuelled Mr Trump’s victory little more than a year ago.

Mr Trump campaigned for Mr Saccone last weekend, urging voters not to “be conned by this guy Lamb.”

Asked about Mr Trump’s approach, Mr Lamb told CNN: “There was a lot of foolishness in this election and a lot of really cartoonish campaigning, and I think by the time of the president’s visit ... there was just a little bit of burnout on that type of campaigning.”

Mr Lamb, a 33-year old former federal prosecutor, asserted his independence from national Democratic Party leaders and studiously downplayed his opposition to the Republican president in the district where Mr Trump’s support has slipped.

But he also offered a full embrace of organised labour, hammered Republican tax cuts and promised to defend Social Security, Medicare and pensions.

Longtime Republican congressman Tim Murphy, who espoused strong anti-abortion views, resigned in October amid revelations of an extramarital affair in which he urged his mistress to get an abortion.

Mr Saccone, a 60-year-old air force veteran turned state politician and university instructor, enjoyed enthusiastic backing from the social conservatives who’ve anchored his state career.

He’s been perhaps at his most animated when emphasising his opposition to abortion rights.

Yet Mr Saccone struggled to raise money, and that consistent fundraising deficit left him with limited resources to air the message he delivered one-on-one: His four decades of experience in the private sector, international business and now the Legislature should make voters’ choice a no-brainer.

TRUMP PICKS TV COMMENTATOR AS TOP ECONOMICS ADVISER
Meanwhile, Mr Trump will name conservative economist and TV commentator Larry Kudlow to replace Gary Cohn as his top economic adviser, according to a report.

Mr Trump offered the White House post to Mr Kudlow on Tuesday and he accepted, CNBC reported.

The announcement could come as soon as tomorrow.

The president praised Mr Kudlow on Tuesday, saying he has a “good chance” of succeeding Mr Cohn.

“I’m looking at Larry Kudlow very strongly. I think Larry Kudlow has a good chance,” Mr Trump said, adding that he was also considering other candidates.

Mr Cohn, the former head of Goldman Sachs, announced he was stepping down last week after Mr Trump announced that he would impose strict tariffs on steel and aluminum imports, a move Mr Cohn opposed.