Former Vice President Joe Biden campaigns for Conor Lamb, right, the Democratic candidate for the March 13 special election in Pennsylvania's 18th Congressional District, during a rally in Collier, Pa., March 6, 2018.
He added at another point: "I hate to put pressure on you, Rick".
Though only a single race is on the ballot, turnout could surpass totals from both of last year's elections.
Public polling shows the race as a toss-up; many closely watching the race - including some Republicans - give Lamb the edge.
"The whole world, remember that".
"Don't forget, this got us elected", he told the crowd outside Pittsburgh. Trump's recently announced tariffs "were calculated, and certainly timed, so he could make this protectionist pitch from this platform in steel country on the eve of a politically-important House race", Axelrod wrote on Twitter.
On Thursday, Trump signed two tariff proclamations to erect a 25% tariff on steel imports and a 10% tariff aluminum imports. But he scrapped his prepared remarks on Saccone, improvising and at one point handing the microphone to Saccone, too.
Montana's at-large district, vacated by Interior Secretary Ryan Zinke, was won by Republican Rep. Greg Gianforte in May, who assaulted a political reporter covering the race the day before the election. His bottom line, though: "I'm not voting for any liberal who's going to advance the Democratic Party agenda".
During the rally, Trump said the South Koreans support his efforts and even credited him with making last month's Winter Olympics a success. "But for getting your votes, he's talking about how much he likes tariffs, which is my baby".
Trump conceded Lamb might not back Pelosi but said most House Democrats will. "I think they wanna do something".
"I think it's a discussion we have to start thinking about".
However, he did reportedly state: "I don't know if this country's ready for it".
One approach might be to make trafficking large quantities of fentanyl a capital crime because even a small amount of the drug can kill, the Post reported.
"Do you think the drug dealers who kill thousands of people during their lifetime, do you think they care who's on a blue-ribbon committee?"
"That's why we have a problem, folks".
Trump also said he hoped to run against Democrat Oprah Winfrey, although the entertainer has ruled out a run despite pressure on her to seek the presidency.
Nearby in DeFelice's upper-middle-class enclave outside Pittsburgh, engineer Carol Heinecke, 57, offered another absolute reason for supporting Saccone: President Donald Trump. Bernie Sanders, Massachusetts Sen. Elizabeth Warren with the slur "Pocahontas".
"Oh I'd love Oprah to win, I'd love to beat Oprah".
"I've already said on the front page of the newspaper that I don't support Nancy Pelosi", Lamb says in the ad.
But he barely mentioned the candidate he was ostensibly there to back, instead spending most of his speech attacking his own possible 2020 opponents and the media, discussing North Korea and unveiling his 2020 slogan ("Keep America great") and touting his new steel tariffs, a policy that plays well in the district and both Lamb and Saccone support.