WASHINGTON -- Before a cheering crowd of firefighters chanting “Run, Joe, Run” Joe Biden stepped to the brink of announcing a presidential campaign Tuesday morning, emphasizing his middle-class roots in a speech that previewed the message he could try to ride to the White House.

Early on in his speech to a firefighters union convention, Biden said he appreciated the energy in the room. “Save it a little longer," he said. “I may need it in a few weeks.”

He quickly added, “Be careful what you wish for.”

The former vice president spoke to several hundred firefighters and their union officials at a Hyatt ballroom near the Capitol, where the International Association of Fire Fighters distributed signs reading “Run Joe Run” and “Fire Fighters for Biden.” He came on stage to the Bruce Springsteen song “We Take Care of Our Own,” which former President Barack Obama featured in his 2012 reelection campaign.

An opening video began with a quote that sounded like a campaign theme.

“Middle-class American folks have never let the country down,” Biden said in the clip. “You have been the centerpiece of everything I have done.”

Biden played up his blue-collar public image and the persona that supporters argue make him the Democrats’ best bet to win back white working-class voters in Pennsylvania and other Rust Belt states that swung the 2016 election to President Donald Trump.

The Scranton-born Biden told the audience that the room “looks like my old neighborhood — we’re ready to take anybody on.”

And he quickly sought to challenge Trump’s hold on middle-class voters, blasting the president for proposing an $845 billion cut to Medicare in his latest budget, unveiled this week. Biden contrasted that proposal with the vast tax cuts Trump approved.

“Who are they asking to pay for it? Middle-class families like you, the neighborhood I grew up in," Biden said.

In many ways, the speech echoed the themes Biden has touched on for months as he has campaigned across the country for fellow Democrats, often serving as a liaison to voting blocs who have increasingly turned away from the party.

“I look around this room, I see the people who built this nation,” Biden said, adding that it wasn’t built by Wall Street bankers or executives.

The event came as Biden allies and donors have expressed rising confidence that the former vice president will soon join the Democratic primary, with many arguing that he represents the party’s safest option to defeat Trump. Biden’s supporters believe he has a broad appeal among Democrats, thanks to his close association with Obama, along with an ability to reach more moderate swing voters. They see Biden as a pragmatic alternative to a field of Democratic hopefuls who have largely embraced sweeping liberal proposals that have excited progressive voters but that critics see as impractical and open to easy attacks.

Workers lay out signs that read "Run Joe Run" ahead of a speech by former Vice President Joe Biden to the International Association of Firefighters at the Hyatt Regency on Capitol Hill in Washington, Tuesday, March 12, 2019.
Andrew Harnik / AP
Workers lay out signs that read "Run Joe Run" ahead of a speech by former Vice President Joe Biden to the International Association of Firefighters at the Hyatt Regency on Capitol Hill in Washington, Tuesday, March 12, 2019.

The union president, Harold A. Schaitberger, said the IAFF would endorse Biden if he runs and said that in his view Biden’s mind was “likely” made up already.

“I’m looking at this as more strategical than really making the ultimate decision,” Schaitberger said. “This is about making sure your plans are made, making sure the boxes are checked, making sure the pieces of the puzzle are in place.”

With the hard-core bases of each party likely to show up in force no matter what, Schaitberger said Biden can win swing voters.

“This is a guy that can bring civility back into the arena,” Schaitberger told reporters, “and it’s somebody who can speak to what I believe is the electorate that’s going to decide the next election. That’s those states right down the heart of America and workers and working families in the places like Pennsylvania, Ohio, Wisconsin, and Michigan, as well as Florida.”

Early polling suggests Biden would enter the race as the Democratic front-runner, bolstered by decades in the public eye and eight years as Obama’s vice president. A Monmouth University poll released Monday found that 28 percent of Democrats and Democratic-leaning independents support Biden, placing him just ahead of 26 percent who would back Sen. Bernie Sanders (I., Vt.).

A host of Pennsylvania Democratic insiders has pledged support for Biden if he does run, showing the kind of appeal he holds within the party’s old guard and, potentially, in key states. Many early polls show Democratic voters are looking most for electability as opposed to any particular ideological position.

Still, Biden has run for president twice before with little success, and much of the Democratic debate so far has been driven by a younger, diverse generation calling for fresh faces and ambitious proposals, not middle-of-the-road safety.

If he does join the contest, Biden would face a field that includes women, people of color, and candidates several decades younger than the 76-year-old former vice president. His record has already faced renewed scrutiny.

But Biden might be one of the few Democrats speaking up for pragmatism.

At one point Tuesday he referred to the ire he’s drawn from some liberals for praising some Republicans, including Vice President Mike Pence.

“Folks, that’s not who we are,” he said.