House Speaker Nancy Pelosi (D-Calif.) and top lieutenants on Wednesday outlined a $760 billion infrastructure package, appealing to President Trump to join in jump-starting a bipartisan priority he once hoped would serve as a key part of his legacy.

The Democrats’ ambitious and at times detailed proposal for building roads, transit systems, airports and water projects came with a glaring — and strategic — omission: They avoided saying how the vast majority of it should be paid for, arguing that Trump should be out front on that issue.

That made for a jarring contrast Wednesday, with House leaders making impassioned pleas for the president to provide leadership on a matter crucial for the nation’s future, even as the Senate considered the Democrats’ articles of impeachment seeking Trump’s removal from office for his actions regarding Ukraine.

“Infrastructure legislation in the past has not been partisan at all. We’ve always been able to come together,” Pelosi said. “The president said, throughout the campaign, that’s something that he wanted to do. So we hope to be joining with him, in a unifying way, not a dividing way.”

It was the latest iteration in a years-long struggle over the direction of a sweeping and much-sought-after infrastructure package, which Trump, Democrats and some Republicans have said is long overdue, even as conservatives have balked at raising taxes to pay for it.

Trump startled some conservative allies earlier in his term by expressing openness to hiking the gas tax, something President Ronald Reagan did in 1983 — but that hasn’t occurred since 1993.

Trump campaigned for office on a promise to lead a $1 trillion infrastructure charge. But his administration in 2018 instead pushed Congress to support a 10-year, $200 billion plan. Officials asserted it would prompt $1.3 trillion in state, local and private spending, an idea rejected by independent economists.

Republicans in Congress showed little appetite for a vast infrastructure spending package in the wake of massive tax cuts for businesses in 2017, which were a higher GOP priority. Still, last April, in a meeting with Pelosi and others, Trump upped the figures even higher, raising the idea of a $2 trillion infrastructure plan. He followed that with a May tweet that read: “I am looking hard at a bipartisan plan of 1 to 2 trillion dollars. Badly needed!”

A spokesman for Senate Majority Leader Mitch McConnell (R-Ky.) referred to comments the senator made in April about the possibility of passing a $2 trillion infrastructure bill.

“My roommate was in the meeting. I haven’t been able to speak to her about it yet,” McConnell said, referring to his wife, Transportation Secretary Elaine Chao. But he said an idea raised by Senate Democrats — paying for new infrastructure by rolling back some of the tax cuts — was a “non-starter.”

“The last thing we want to do is step on all of this growth,” McConnell said then.

Democrats say they’d like to see Trump step forward.

House Majority Leader Steny H. Hoyer (D-Md.) reiterated Wednesday something he told Trump following their April meeting: that no Democrat or Republican in the House or Senate “is going to support $2 trillion if you’re not leading the way on how we raise that dollar.”

White House spokesman Judd Deere dismissed the Democrats’ plan as “the Green New Deal 2.0,” adding that Trump has “already taken significant regulatory action” to speed infrastructure projects and considers bipartisan efforts in the Senate more promising.

A Transportation Department official said that “the secretary and the administration have said multiple times that nothing is off the table when it comes to paying for infrastructure” but noted that “this proposal does not appear to have been drafted in a bipartisan fashion.”

House Ways and Means Committee Chairman Richard E. Neal (D-Mass.) said he thinks a bipartisan deal is possible — and that holding back Democratic declarations on how to fund infrastructure will help that process along.

“I think that there’s some room here,” Neal said. “I think it’s really important that we not volunteer a revenue stream until the administration reaches an agreement with us.”

Neal said his committee would negotiate with Republicans “over what the revenue stream ought to be . . . My hunch is that’s the best way to do it,” noting that a Republican leader told him “there could be up to 70 votes for an infrastructure bill in the House.”

“What we’re looking for here is an agreement that we can then take to the public, between the two sides, on how best to pay for it, so there’s not one-upsmanship,” Neal said.

The Democratic plan seeks to expand and rebuild infrastructure while tackling the dangers of climate change.

“We’ve been living off the legacy of Dwight David Eisenhower, with small tweaks, for 75 years. It’s falling apart,” said Rep. Peter A. DeFazio (D-Ore.), chairman of the House Transportation Committee. “There are so many ways we can deal with the climate crisis by solving our congestion and infrastructure crisis.”

DeFazio cited the example of a sewer district in New Jersey that was able to rebuild its system with the help of a federal loan.

“They are able to do it without raising rates because they’re now capturing their methane and generating electricity,” DeFazio said, pointing to new wastewater initiatives among the proposals in the Democrats’ framework.

The five-year plan would include $329 billion for building highways and making road safety improvements; $105 billion for transit; $86 billion to expand broadband; $55 billion for rail; $50.5 billion for clean water and wastewater projects; $30 billion in airport funding; and billions more for other environmental and public safety initiatives.