Washington:Pennsylvania's closely watched special congressional election was too close to call Tuesday, but regardless of the outcome Democrats made dramatic inroads with voters who supported President Donald Trump , a trend that bodes poorly for Republicans ahead of November mid-term elections.
With more than 99 percent of precincts reporting in southwestern Pennsylvania's 18th congressional district, Democrat Conor Lamb was leading his Republican rival Rick Saccone, a Trump ally, by a mere 847 votes -- out of more than 224,000 ballots cast.
The race was so close that the results from some 3,000 outstanding absentee ballots in three of the district's four counties would likely decide the outcome.
The processing and counting of those absentee ballots could take "several hours," a local election official from Washington County told CNN.
The election, seen by many as a referendum on Trump and a Republican Party fighting to maintain its control of Congress, was taking place in a working-class district that Trump won by about 20 points in 2016, suggesting the latest developments were good news for the opposition party.
With the race in the balance, Saccone, whose campaign drew criticism from Republican strategists for its lackluster performance in recent weeks, told his followers that "It's not over yet."
"We're not giving up," Saccone added.
But the performance by Lamb provided the broader takeaway.
"It's a win for the Democrats even if they don't actually win this," Kevan Yenerall, a political science professor at Clarion University in Pennsylvania, told AFP.
For Republicans, it sets off alarm bells.
"If you're a Republican and you're in a marginal, competitive district... you're going to be concerned," he added.
The 33-year-old Lamb, a former federal prosecutor and US Marine officer, ran a surprisingly strong race against conservative state representative Saccone, 60.
His performance in a district held by Republicans for the last several elections has the potential of shaking up the political landscape on a national level.
And it would reassure Democrats they can win in what has been considered Trump country, giving them a surge in enthusiasm, fundraising and grass roots activism as they head toward November's all-important mid-term elections.
Veteran political analyst Stuart Rothenberg said it was notable that in a district long dominated by Republicans, the party's voters "either stayed home or flipped to Lamb."
Who wins the district was immaterial, Rothenberg argued on Twitter. "The outcome is clear."
Trump had endorsed Saccone and made an 11th-hour campaign stop with the candidate.
But Lamb's unexpectedly strong performance -- the race was considered a toss-up going into Tuesday -- underscored the challenges that Republicans face as they prepare to defend their majority in both the Senate and House of Representatives in November.
The party occupying the Oval Office tends to lose seats in the first mid-terms after winning the presidency.
With chaos swirling in the White House, Trump's approval rating under water, and a special prosecutor investigating potential collusion between Trump's campaign and Russia, Democrats are counting on a domino effect at the polls to send them back to power in Congress.
Republican organizations have poured millions of dollars of outside money into the race in the hopes of dragging Saccone across the finish line and signaling that their position ahead of the mid-terms is not as precarious as Democrats suggest.
Democrats have noted that Lamb's blue-collar roots, support of organized labor and moderate political views were helping him win crossover support in conservative areas.
In District 18, several of Trump's campaign promises have resonated with voters -- in particular, his call for restricting immigration, supporting gun rights, and bringing back jobs in the coal and steel industries.
Lamb has worked to avoid alienating Trump supporters, and downplayed the idea that the Pennsylvania election is a referendum on the controversial commander-in-chief.
The district's voters "overwhelmingly want me to work with the president," Lamb said after casting his ballot Tuesday.
Trump has described Saccone as "very strong on experience" while painting Lamb as "weak on crime" and border security.
"The economy is raging, at an all time high, and is set to get even better. Jobs and wages up," Trump tweeted on Tuesday.
"Vote for Rick Saccone and keep it going!"
Lamb was endorsed by the main mineworkers and steelworkers unions in the region, whereas Saccone has had a tempestuous relationship with organized labor.
Democrats came close to flipping Republican seats several times in US House special elections last year, in Georgia, Kansas, Montana and South Carolina. While those Democrats ultimately fell short, they fared better than Hillary Clinton did against Trump in those districts in the 2016 presidential race.
Pennsylvania 18's previous congressman, Republican Tim Murphy, resigned last year amid an adultery scandal. APP/AFP