They are a youthful bunch — at least by the mossy standards of the U.S. Senate.

Among the 11 new senators elected in Tuesday’s midterm elections, eight are under age 60, and one is just 37. And after their victories, the Senate’s new freshmen exuded the kind of can-do confidence that comes only with youth. Or with not understanding what they’ve gotten themselves into.

“We have signed up to be the tip of the spear . . . to pick the shackle of gridlock and to fundamentally change the dysfunction of Washington, D.C. — and we have indeed reached that historic day. We have realized the success of that movement,” said Rep. Cory Gardner (R), after he beat an incumbent Democrat to win a Senate seat in Colorado. “Tomorrow, we go to work.”

The new freshmen — including 10 Republicans and one Democrat — seem different, at first glance, from the class with tea party influences that joined the Senate in the GOP wave of 2012.

Most of these new members already have much experience in government. Three have held positions at the state level. Five are members of the House, where the Republicans among them have tended to back Speaker John A. Boehner (R-Ohio) in his long and often fruitless fights with his own tea party wing.

How the demographics of the Senate have changed in 20 years

On Election Night, many of the Senate’s freshmen seemed to think Washington’s greatest problem was a lack of competence. The current legislators, they thought, lacked the focus or the stomach to find long-term solutions to big problems.

Several spoke of returning the Senate to its old traditions, in which the two parties worked together on far-reaching reforms.

“I’m the only chemical engineer in Congress,” said Rep. Steve Daines (R), after winning a Senate seat in Montana. “Engineers are trained to solve problems, not to win arguments.”

The problem is that these freshmen are coming to a Senate that may not remember how the good old days worked.

After a series of wave elections, retirements and deaths, there are far fewer veterans who saw those dealmaking times up close. When the new class takes office, half of all senators will have joined since 2008, in an era dominated by partisan gridlock.

The leaders who presided over the Senate’s descent into inaction — Sens. Mitch McConnell (R) and Harry M. Reid (D) — will also be its leaders yet when the freshmen arrive. All they will probably do is switch places, with McConnell taking over Reid’s role as majority leader and Reid becoming leader of the minority.

Still, McConnell has said that he will restore the Senate to its old ways. And the makeup of the new class was enough to make some current senators hopeful that things would really change.

From the Senate to gubernatorial races, here are the key Republican winners from the 2014 midterm elections. (The Washington Post)

“From my perspective, many of the new members are pragmatic. They’re conservative, but they’re pragmatic conservatives,” said Sen. Susan Collins (R-Maine), a three-term incumbent who was reelected Tuesday. “I see the [Republican] caucus as a caucus that wants to get things done and that will not be as ideologically driven as one might think.”

The great outlier in the Senate’s Class of 2014 is Gary Peters (Mich.), the lone Democrat.

Peters, a former state lottery commissioner, has compiled a moderate to conservative voting record during three terms in the House. He easily won the race to replace Sen. Carl Levin (D), a Democratic titan who has been in the Senate since 1979. Now, as the Senate’s only freshman Democrat, Peters will outrank only the teenage pages.

Among the new Republican senators who now serve in the House, only one has been there longer than four years: Rep. Shelley Moore Capito (W.Va.), serving since 2001.

Capito, whose father was also a congressman and a West Virginia governor, became the first woman ever elected to the Senate from the Mountain State. In Congress, Capito has been something of a wild card. She has drawn the ire of the tea party for opposing cuts to some federal programs. She also does not think that Roe v. Wade should be overturned, though she has voted to limit access to abortion. In her victory speech Tuesday, Capito stressed the need for “bipartisan solutions.”

The other House members elected to the Senate included Gardner and Daines, plus James Lankford (Okla.) and Tom Cotton (Ark.). At 37, Cotton is the youngest member of the new Senate class — a graduate of Harvard and Harvard Law School who also served in Iraq and Afghanistan with the Army.

Cotton had come to the attention of conservatives in 2006 after he e-mailed a letter to the New York Times that was critical of it decision to expose U.S. strategy. “You may think you have done a public service, but you have gravely endangered the lives of my soldiers and all other soldiers and innocent Iraqis here,” he wrote.

The letter was posted online and went viral within conservative circles, launching his political career. In this Senate campaign, Cotton emphasized his military service by donning his campaign bus with a camouflage pattern and a red,white, and blue bootprint on the front.

In his victory speech, Cotton sounded dour and dire. He told supporters that they had chosen to live “as free men and women under law” and to control government before government controlled them.

“We reject the pessimism and the defeatism inherent in the other way of governing, the centralizing and bureaucratic rule of presumed elites,” Cotton said. “We may gain some material security by choosing this other form of government, but under it there is no true security for anyone”

On Wednesday, Republican leaders were hopeful that the House members would be willing to follow McConnell’s leadership in the Senate. In the House, most of them have stuck by Boehner in his fights with breakaway conservatives.

“They definitely are all, I would say, in the constructive category” rather than playing destructive roles in the Republican caucus, said Rep. Devin Nunes (R-Calif.), who has also been on Boehner’s side in most of these fights. “Clearly, they know that if you don’t use your votes as a majority, you effectively turn control . . . over to the other side.”

The three freshmen who have held an office at the state level include Thom Tillis (R), speaker of the North Carolina state House, and Republican Mike Rounds in South Dakota, who served two terms as governor before running for Senate.

The best-known of that group, however, is probably Joni Ernst, an Iowa state senator who won a Senate seat held by a retiring Democrat. Ernst served as a a lieutenant colonel in the Iowa Army National Guard. But she was most famous for a TV ad that capitalized on her childhood experiences castrating hogs on an Iowa farm.

In her victory speech Tuesday night, Ernst spoke with amazement about the arc of her life: “It’s a long way . . . from the biscuit line at Hardee’s to the United States Senate,” she said.

Then Ernst repeated the line from the hog ad that had made her famous: “We are heading to Washington, and we are going to make ’em squeal!”

The last two freshmen are David Perdue (R), a longtime business executive who won the Senate seat in Georgia, and Ben Sasse (R), the winner in Nebraska. Sasse, 42, is a Harvard graduate who worked for the George W. Bush administration in Washington and is now president of a small Nebraska college.

Sasse, who won a cakewalk race, offered an enthusiastic, if vague, description of the tasks he would tackle in Washington.

He was sure of one thing: Whatever he did, it would be something big.

“My pledge tonight is that I want to stand with, and engage, and debate, and wrestle together with the bigger issues that we face,” Sasse told his supporters Tuesday. “And we are going to keep on living by the ‘Go Big or Go Home’ motto.”

Paul Kane, Ed O’Keefe, Nia-Malika Henderson, Ben Terris, Hunter Schwartz, Katie Zezima, Sean Sullivan and Jaime Fuller contributed to this report.