Washington (AFP) - US President Donald Trump's Republican Party was on course Wednesday for a stunning defeat in a key special congressional election in Pennsylvania, adding to the turmoil engulfing his administration after the sacking of Secretary of State Rex Tillerson.
Democrats exulted in the stunning performance by one of their own in a race that has taken on national implications, insisting that their unexpectedly strong showing in Trump country -- unthinkable a year ago -- bodes well for them ahead of November's midterm elections.
With all precincts reporting, and more than 240,000 ballots cast Tuesday, Democratic candidate Conor Lamb was leading Republican Rick Saccone by 579 votes, or 49.8 percent to 49.6 percent.
As county officials counted provisional and absentee ballots that will likely determine the outcome, Lamb declared victory in the wee hours of Wednesday, in a district Trump won by nearly 20 points in the 2016 presidential contest.
The New York Times later called the race for Lamb, saying his lead "appeared insurmountable."
And Lamb's party swiftly proclaimed that Trump and his Republicans could face a political reckoning this year -- with control of Congress up for grabs.
"As we head into the 2018 midterms, the momentum is undeniable for Democratic candidates running up and down the ballot," Democratic National Committee head Tom Perez said.
"Pennsylvania is just the beginning."
- 'Wake up call' -
The performance by Lamb -- a 33-year-old former federal prosecutor and US Marine officer -- was an eye-opener on multiple fronts.
Not only did it show Democrats have reconnected with organized labor, it demonstrated that moderates who fought for economic fairness could resonate with older, white, male working-class voters -- the very segment of America's electorate that swung to Trump in 2016.
Somber Republican leaders were forced to acknowledge that, regardless of the District 18 outcome, Lamb had dealt a sharp blow to their prospects of maintaining control of the Senate and House of Representatives.
"This should be a wake up call," House Speaker Paul Ryan told Republican lawmakers in a closed-door conference, according to a person in the room.
Speaking to reporters, however, Ryan sought to downplay the impact, suggesting Lamb was a Democrat unusually well-suited for his district, who ran a pro-life, pro-gun, anti-establishment campaign.
"Both of these candidates ran as conservatives," Ryan said of Lamb and Saccone. "I just don't think you're going to see that across the country" in November.
- 'No district is safe' -
Democrats exulted over the political ramifications of having potentially ousted a Republican in a conservative, working-class bastion.
"The results in Pennsylvania spell disaster for Republicans in November," said Bradley Beychok, who heads the pro-Democrat political action committee American Bridge.
"If they can't win in a longtime Republican stronghold, no district is safe."
All 435 House seats are up for election every two years. Senate terms are for six years, and 35 of the 100 seats are in play in November.
Trump campaigned in person for Saccone, a culturally conservative state representative who had been accused of running a lacklustre campaign.
But the election was held just as the White House was whipsawed by political upheaval including a series of staff ousters, including Trump's sacking of Secretary of State Rex Tillerson on Tuesday.
Trump's own low approval rating no doubt contributed to Saccone's poor showing, though White House spokesman Raj Shah put a brave face on it.
"The president's engagement in the race turned what was a deficit for the Republican candidate to what is essentially a tie," Shah said.
But Lamb, acutely aware of how his district voted in 2016, refused to pile on against the president during the campaign, seeking to minimize the political divisions that have set many Americans on edge.
"I know people voted for the president and voted for me," Lamb told CNN.
His performance in a conservative stronghold -- Democrats had not even fielded a candidate against the Republican incumbent in recent elections -- suggests far more congressional districts might be in play in November than the 24 seats necessary for Democrats to reclaim the House.
The party in power in Washington traditionally loses seats during the midterm elections of a president's first term. But there are signals that 2018 could be a banner year for Democrats.
They over-performed in five special elections in deep-red districts last year, including in Georgia, Montana and South Carolina. And in a special election last December, Doug Jones became Alabama's first Democratic senator in 25 years.
Strategists point to unprecedented Democratic grass-roots activism, strong fundraising, and competitive candidates that have combined to animate voters this year.
"We knew the midterms were going to be difficult," House Republican Tom Cole told CNN, acknowledging that "our majority is at stake."
"We're certainly not in a state of denial or complacency on our side," he said.