In a conference room high above Market Street, Pennsylvania's heavy-hitting Democrats, including two congressional candidates and former Gov. Ed Rendell, gathered last week to discuss how their party can score a big win if it gains control of the U.S. House in November's elections.

Immigration, health care, and guns have been among the hot-button topics of this campaign, but the focus at the meeting Tuesday was on something else:

Infrastructure.

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"Infrastructure is not the thing most people lead with," said Earl Blumenauer, an Oregon congressman who was in Philadelphia as part of a nationwide tour to convince sitting Congress members and Democratic candidates that roads, bridges, and railroads must be a priority next year. "But it'll take over a town meeting. There is uniform interest."

Democrats see an infrastructure bill as something they could get through a Republican-controlled Senate and Trump's White House. Infrastructure improvements have traditionally drawn bipartisan support, and although the president has been quiet on the issue recently, he ran in 2016 on a $1 trillion proposal for infrastructure spending.

"I believe if we took back the House and wrote a good, balanced infrastructure bill, you would get support from the Senate," Rendell said, "including several Republican senators."

There is widespread agreement that rail, roads, and bridges nationwide need face-lifts. Both parties have stated that they support comprehensive infrastructure packages. Last week, U.S. Rep. Mike Kelly, a Pennsylvania Republican, said he would want an infrastructure bill to be a Republican priority in 2019, as well, should his party hold the House.

"For the country that we are, for the economic engine that we are, for the success that we have, our infrastructure is failing," he said.

The retiring head of the House Transportation Committee, Bill Shuster (R. Pa.), put out a discussion document in July meant to spur movement on an infrastructure bill. Democrats have proposed a $1 trillion package.

In a report from the American Society of Civil Engineers that gave the nation's infrastructure a score of D-plus last year, the group found that the country's roads were "in poor condition, chronically underfunded, and are becoming more dangerous." More than half the nation's highway bridges are in fair or poor condition, according to the Federal Highway Administration. Amtrak has proposed as much as $153 billion in work on the heavily traveled Northeast Corridor.

SEPTA's general manager, Jeff Knueppel, attended Tuesday's meeting and said his agency's Regional Rail is strained by growing ridership on train cars that date from the Nixon administration. Leo Bagley, PennDot's deputy secretary, said Pennsylvania has 4,500 structurally deficient bridges.

Yet, infrastructure hasn't been at the forefront of congressional campaigns. House Minority Leader Nancy Pelosi mentioned campaign finance reform, drug prices, and gun control in an interview with Politico this month where she outlined the priorities of a Democrat-controlled House, but not infrastructure. The topic doesn't even appear on a list of voters' priorities in ongoing polling conducted by Gallup.

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"Immigration, health care, trade have sucked the air out of the room," said Dan David, a Republican running for the Fourth Congressional District seat. "The voters can only concentrate on so many issues at once."

When candidates talk with voters, though, conversation often turns to infrastructure, whether it's the quality of roads or access to jobs. Among those attending Tuesday's meeting were Madeleine Dean and Mary Gay Scanlon, Democrats hoping that voters in the Fourth and Fifth Districts, respectively, will send them to Congress. Dean in particular focused on densely developed areas in her district, such as King of Prussia and Pottstown, that would benefit from investment in transportation. Light rail that would connect Norristown and King of Prussia has been planned for years, but SEPTA has not locked down funding for the $1.1 billion proposal.

"When I'm knocking on doors, people are talking about infrastructure," Dean said. "People are crying for it."

Blumenauer is on the House Ways and Means Committee, not Transportation, but his committee could secure financing for an infrastructure bill.

"It would be my intention that we would start from the beginning of the Congress and have at least one hearing every single week listening to Americans about what they want, what they need, and what they don't," he said.

The gathering Tuesday at Rendell's law firm, Ballard Spahr, was a way to discuss Pennsylvania's needs, and strategize financing. The former governor had plenty of ideas:

Remove the ban on tolling federally funded highways. Establish a national infrastructure bank. Create an infrastructure capital budget.

Much federal highway money comes from a gas tax of 18.4 cents a gallon that hasn't gone up since 1994.

"Why would anybody think that our gas tax wouldn't have needed to go up during that time period?" he asked.

Just increasing the gas tax, though. wouldn't do. Low fuel costs and more fuel-efficient vehicles have made the gas tax an old way to raise funding, and Blumenauer emphasized the need for a tax based on how many miles a vehicle travels.

"The bottom is going to fall out of our funding model," he said. "I think there is a road-user charge in our future sooner than most people think."

The price tag associated with infrastructure can quickly turn a politician's feet cold, and at Tuesday's session, officials emphasized that such spending can't add to the nation's deficit.

"When people want to look at what the initial cost is, that sticker shock is what gets leadership to run away," David said.

While voters may not describe infrastructure as one of their priorities, and politicians may balk at the cost, the way to sell the need for a comprehensive infrastructure bill is to focus on outcomes, said Drew Hammill, a spokesperson for Pelosi. Voters do care about jobs and wages, and Democrats are selling infrastructure investment as a way to address both.

"We think the best way to raise wages is to rebuild America," he said. "It's getting at it in a different way, a more roundabout way."

Staff writer Jonathan Tamari contributed to this article.