Rep. Madeleine Dean (D-Pa.) stopped to ponder the question: Has her historic class of freshman Democrats changed Washington, or has this town changed them?

“That’s a great question,” the Democrat from Philadelphia’s suburbs responded. “I think we’re changing things. I really do.”

Her several-second pause revealed the growing pains of the class of more than 60 Democrats who blew into Washington in January with seemingly limitless beliefs and ambition for how much they wanted to reshape Congress.

Other freshmen voiced similar optimism, mixed with even more hesitation. The several-dozen first-time legislators are still learning two new jobs at once — being legislators and handling constituent service — all while trying to position themselves for reelection.

Some rookies have struggled with the inside politics of a byzantine institution that requires just as much glad-handing to senior lawmakers as it does policy expertise.

They discovered that private discussions are not always so private, as internal rivals might leak a story to cut off their maneuvering. And their bloc lost two members — one to resignation after an extramarital affair was unmasked and another to a party switch to the GOP.

And all are learning the hard way how limited their power is, with hundreds of House-passed bills gathering dust in a Republican-led Senate that has no interest in the freshmen’s agenda. Even after a final moment that rallied the group together — every freshman Democrat voted to impeach President Trump — Majority Leader Mitch McConnell (R-Ky.) has made plans for a speedy acquittal in the Senate.

“I feel like we are changing Washington, but it’s not nearly as fast as everybody might like it to be,” Rep. Susan Wild (D-Pa.), whose district anchored around Allentown is north of Dean’s.

It is not what they expected when they delivered the majority to Democrats and returned the gavel to House Speaker Nancy Pelosi (D-Calif.), having done so in a symbolic fashion that suggested a new power structure at hand.

This crop included a group of national security experts who flipped longtime Republican districts, such as Virginia Reps. Elaine Luria, who served on nuclear submarines in the Navy, and Abigail Spanberger, a former CIA analyst.

They are younger than typical politicians, doubling the size of a caucus, the Future Forum, that had been created four years ago as a refuge for younger Democrats who felt powerless. Their youngest member, 30-year-old Rep. Alexandria Ocasio-Cortez (D-N.Y.), became an instant political celebrity for the fierce liberal activist wing, branding her quartet of similar-minded newcomers “the squad.”

During Trump’s Feb. 5 State of the Union address, the first-term women led a joyous dance on the House floor in suffragist white when the president said there are “more women serving in Congress than at any time before.”

Rep. Haley Stevens (D-Mich.) summed up their ambitions in an interview with The Washington Post’s Dan Balz on Jan. 3 by suggesting her class would be more impactful than the reform-minded Class of 1974 that swept into office following Richard Nixon’s resignation that August in the face of a certain impeachment.

“We are the doers. We’re the defenders of democracy. We’re here to make it work,” Stevens, now 36, told Balz a couple hours before taking her first oath of office.

As this first year ended, Republicans accused Democrats of doing nothing more than impeaching Trump and not advancing their “make-it-work” agenda. On Thursday, House Minority Leader Kevin McCarthy (R-Calif.) said the U.S.- Mexico-Canada trade agreement could have been moved months ago but instead Pelosi waited until after Wednesday’s impeachment votes, a notion Democrats dismiss after hard-fought negotiations with the Trump administration.

It served as almost a trade-off to those freshmen facing difficult reelections and needing to point to some legislative victories, McCarthy said. “Could it be those who sit in the districts that President Trump carried, that wanted USMCA, had to pledge a vote for impeachment to get USMCA?” he asked.

The first fissures among the freshmen appeared in late February, when many from Trump districts sided with Republicans to amend the long-sought legislation to enhance background checks on gun purchases. It added a measure requiring that Immigration and Customs Enforcement be notified if an immigrant in the country illegally seeks to purchase a gun. That provision infuriated Ocasio-Cortez and liberals, who nearly took down the entire bill.

These Democrats now admit how little they understood process at the outset. “You’re talking about an accelerated course of study on how to be a legislator. I was never a legislator before and so much of this is about learning how to do basically two major jobs,” said Rep. Elissa Slotkin (D-Mich.).

Slotkin, who supported the GOP vote, previously worked as a CIA analyst and Middle East policy expert at the Pentagon before winning a central Michigan district that Trump won by 7 percentage points.

By midsummer, the freshmen split bitterly when their Democratic colleagues in the Senate linked arms with Republicans to pass a less ambitious bill to deal with the border crisis. One group of freshmen wanted to stand and fight for a better deal; the other accepted the Senate bill as the best that could be done.

It came as Ocasio-Cortez’s “squad” engaged in a public clash with Pelosi, and a lot of dirty laundry got aired.

“Nothing is private, which is very unfortunate, because you want to be able to have honest conversations with your colleagues, and that’s definitely something that’s been a hard lesson,” said Rep. Debbie Mucarsel-Powell (D-Fla.), a first-time candidate who won a longtime GOP seat stretching to Key West.

The final week epitomized the entire year. On Monday, leadership unveiled a $1.4 trillion budget bill that included dozens of tax changes, health policies and other provisions that had never even made it out of committee.

They voted on the bill about 21 hours later.

“It’s a perfect metaphor for what so many of us find so wrong with how this place operates,” said Rep. Dean Phillips (D-Minn.), who won a GOP seat in the Twin Cities suburbs.

Then came the impeachment votes, the most partisan moment of their first year in Congress. But the experience also helped fuse the freshmen back together. On Sept. 23, seven freshman national security experts from swing districts published an op-ed in The Post backing the impeachment inquiry. The next day, Pelosi formally launched the probe.

Yes, one of their own, Rep. Jeff Van Drew, who won a southern New Jersey district Republicans had held for 24 years, broke ranks and crossed the aisle to join the GOP on both articles.

But every single other freshman supported impeaching Trump for abuse of power, something that many had been resisting, but ultimately, it was in their DNA. They were here to try to change Washington, political consequences be damned.

“Their future is on the line by taking a principled position. And no matter what people think of this issue and this president, that type of courage should be celebrated. I wish there was more of it here,” Phillips said.

Mucarsel-Powell said that it was the right ending to a tumultuous year for the freshmen.

“Leaving today, I can tell you that I feel closer to my colleagues than I have, than I did six months ago. Absolutely,” she said.