Bliss, who heads the main super PAC for House Republicans, arrived at his office at 6:30 a.m. and played an internet clip of Lamb, a telegenic 33-year-old former federal prosecutor and Marine veteran, speaking at a Democratic gathering. Then Bliss pulled up a video on social media of the Republican candidate he was tasked with helping, 59-year-old state legislator Rick Saccone.

“I realized this would be a race,” Bliss said.

Since that November morning, the Republican Party has launched a massive campaign to save a House seat here in the heart of Trump country. A loss in the March 13 contest — coming just months after the party’s embarrassing defeat in the Alabama Senate race — would portend a potential blowout in the November midterms.

Nearly every corner of the GOP is involved. The White House is working closely with Saccone and dispatching President Donald Trump and Vice President Mike Pence to the suburban Pittsburgh district on his behalf. The House Republican campaign arm has begun a $2 million TV offensive and is aggressively pressing party lawmakers to help fund the candidate. Bliss’ group, Congressional Leadership Fund, is deploying dozens of field staffers, who braved frigid winds last weekend as they canvassed for votes.

By the end of the weekend, Republicans were outspending Democrats on TV by a ratio of nearly 5-to-1. The GOP push will only intensify: The Republican National Committee is set to invest about $1 million, much of it on digital, field and other get-out-the-vote activities.

The blueprint, described by over a dozen senior party officials and strategists, underscores the enormous stakes for the party. With Republicans already deeply anxious about the midterms, a loss in Pennsylvania’s 18th District, which Trump won by 20 percentage points, would show that the party is vulnerable even in deep conservative territory and that a political bloodbath could be in the making.

Republicans have reason for alarm. In January, America First Action, the principal pro-Trump outside group, quietly conducted a poll that found Saccone with a single-digit lead over Lamb, who hails from a well-known political family in southwestern Pennsylvania.

“This is a litmus test for the political year,” said Pennsylvania GOP Rep. Glenn Thompson, who spent Friday afternoon at a rally for Saccone headlined by Pence. “Obviously, there’s a lot at stake for everybody in politics with this special election race.”

Pence lavished praise on Saccone during a 22-minute speech at the packed Bethel Park Community Center, where some attendees had waited over an hour in line to get inside. The vice president said the candidate has the administration’s “total support” and that Trump needed him in Congress to pass his agenda. Pence tore into Lamb repeatedly, deriding him as a pawn of House Minority Leader Nancy Pelosi (D-Calif.) and accusing him of ducking on issues like gun rights and whether he supports Obamacare.

“I won’t talk about Rick’s opponent much today, because Rick’s opponent won’t tell Pennsylvania much about himself or what he believes,” Pence said. Before speaking, the vice president hosted a backstage fundraiser for Saccone that netted about $250,000, according to one person who attended the event.

Saccone spoke for only about three minutes, vowing to be a loyal Trump ally and promoting the administration’s recently passed tax reform bill, before introducing Pence. The disparity spoke to the national party’s imprint on the race: Saccone is the candidate, but Washington Republicans are playing an outsize role in his campaign.

Indeed, Pence’s visit was the latest plank in what White House officials describe as a multipronged effort to boost the candidate. Last month, Trump appeared with Saccone during an ostensibly official visit to a southwestern Pennsylvania manufacturing plant. Trump is expected to return to the district before the special election, and Pence may as well. The White House is also considering deploying Cabinet members to campaign for Saccone.

The White House political affairs office is also involved. Its director, Bill Stepien, pressed Saccone campaign officials during a recent conference call to step up their fundraising.

The White House involvement is partly a response to appeals from House Republicans. At a retreat at Camp David last month, House Majority Leader Kevin McCarthy of California outlined the party’s challenges in the district, including potential complications in defining Lamb as too liberal for the conservative district. McCarthy, according to a person familiar with the discussion, also noted that Democratic voters are more mobilized at the moment than Republicans.

Fundraising is another issue. Through the end of December, Saccone had raised only about $215,000 — less than half of what Lamb took in. Racing to fill the gap, the House GOP Conference held a fundraiser for the candidate in Washington last month, and party leadership is slated to host another one for him on Feb. 14.

The fundraising effort took center stage during last week’s congressional Republican retreat in West Virginia. National Republican Congressional Committee Chairman Steve Stivers (R-Ohio) kicked off a 90-minute presentation on the electoral landscape with an appeal for lawmakers to donate to Saccone. One lawmaker offered money on the spot.

Saccone and Lamb are seeking to replace former Republican Rep. Tim Murphy, who resigned in October amid allegations that he had asked a woman with whom he was having an affair to get an abortion.

Lamb is shrugging off the national Republican assault. During a brief interview on Saturday afternoon, Lamb, a first-time candidate who is the grandson of a former state Senate majority leader and the nephew of the Pittsburgh city controller, said he was not bothered nor surprised by the vice president’s attacks a day earlier.

“It’s not affecting me day to day,” said Lamb, who spent part of the day opening a new campaign office in Washington County. Voters, he added, “know me, they know my family. ... They don’t care what Mike Pence says.”

Lamb, perhaps wary of being tied too closely to Democratic leadership while running in a conservative district, declined to answer directly when asked whether he wants additional help from his national party to counter the Republican barrage.

“We’re running a local campaign,” he said.

Lamb is walking a fine line, carefully avoiding overt criticism of Trump, who remains popular in the district, while also engaging the Democratic voters whose support he needs. The candidate has said he’s willing to work with the president on issues affecting Pennsylvania’s 18th District, an area filled with union households that encompasses Pittsburgh’s southern suburbs. Those include passing an infrastructure bill and combating the opioid crisis.

Yet Lamb has also blamed Washington Republicans for failing to pass an infrastructure package one year into Trump’s presidency.

Many Republicans are convinced that the district’s pro-Trump tilt will be enough to put Saccone over the top. But others are concerned that Lamb’s stylistic talents as a candidate make him a serious threat.

Bliss immediately mobilized a field plan after Lamb became the Democratic nominee. He asked the group’s national data director, Ryan Terrill, to move to Pennsylvania full time beginning in January and said he wanted to knock on 250,000 doors by the time of the election — frigid weather or not.

Since then, the group has deployed about 50 staffers to the district and opened two offices. On Saturday morning, Terrill and another Congressional Leadership Fund staffer, Mandy Abbott, went to Greensburg, a Pittsburgh exurb, to hit the streets in search of votes.

It was about 20 degrees and the sidewalks were icy, but the group had developed techniques for combating the cold. Field workers travel in pairs, allowing them to take turns getting breaks every 15 minutes. They have also found that the colder it gets, the more quickly they lose battery life on their iPhones, which the staffers use to determine which houses to contact. So as soon as they jump in their cars for a break, the field workers charge their phones.

As they trudged through Greensburg, Terrill and Abbott hung door placards that took aim at a familiar Republican target: Pelosi. The hangers describe Lamb as a “rubber-stamp” for the Democratic leader — a message that grew directly out of focus groups the super PAC had conducted in January, when voters expressed widespread antipathy toward Pelosi.

Some of the people whom Terrill and Abbott approached were familiar with the line of attack, which also shows up in Congressional Leadership Fund TV ads saying that Lamb “would be one of Nancy Pelosi’s sheep.” When Abbott offered one man the campaign literature, he turned it down, saying he already knew he wouldn’t be supporting the Democrat.

“We don’t need more sheep like Conor Lamb,” he said.