Colorado’s congressional delegation kept the same partisan distribution — four Republicans and three Democrats — on Tuesday and every incumbent who sought reelection won another term, including U.S. Rep. Mike Coffman, the Aurora Republican who triumphed by a wider than anticipated margin in the face of one of the most hard-fought challenges in the country from former state House Speaker Andrew Romanoff.

Despite anticipation that the 6th Congressional District race might go down to the wire — party registration in the suburban seat is nearly evenly divided between Republicans, Democrats and unaffiliated voters and it was the most expensive congressional race in state history — Coffman beat Romanoff handily to win a fourth term, with 51.9 percent of the vote to the Democrat’s 43 percent, according to unofficial figures posted at press time by the Colorado Secretary of State’s office. (Green Party nominee Gary Swing got 2 percent and Libertarian Norm Olsen had 3.1 percent.)

“Let us now move forward past this election, past the tough debates, past those miserable 30-second ads, and past the bitter emotions that have divided us,” said a triumphant Coffman at the statewide Republicans’ election night watch party at the Hyatt Regency Denver Tech Center, “to unite behind creating a better, more inclusive America, an America that recognizes the value of hard work, of strong families and of a faith in God.”

Coffman thanked Romanoff for running and added, “This has been a very tough race, and I am a better candidate for it.”

At his own packed election night party at an Aurora barbecue restaurant, Romanoff congratulated Coffman and asked his supporters to do the same.

“I happen to believe this is the best system of government in the world. The outcome didn’t quite go the way we wanted,” he said.

Voters in the 4th Congressional District, covering Weld County, portions of Douglas County and the Eastern Plains, elected Republican Ken Buck to replace U.S. Rep. Cory Gardner, who won a Senate seat the same night when he defeated incumbent U.S. Sen. Mark Udall.

Incumbent Democrats U.S. Reps. Diana DeGette, Jared Polis and Ed Perlmutter won their reelection bids by double digits. Republican U.S. Reps. Scott Tipton and Doug Lamborn similarly dispatched their opponents by out-sized margins.

“I have some good news for everybody,” Buck, the Weld County district attorney, told Republicans at the GOP’s watch party. “Tomorrow morning when you wake up, there will be no political ads!”

Buck, who narrowly lost a bid to unseat U.S. Sen. Michael Bennet four years ago, hopscotched his way into the seat Gardner vacated, first emerging as the frontrunner to take on Udall and then, after dropping from the Senate race the day after Gardner jumped in, winning a primary for the chance to run in the heavily Republican district.

Buck won with 64.9 percent of the vote over the 29.1 percent that went to Democratic challenger Vic Meyers. Libertarian Jess Loban scored 3.25 percent and unaffiliated candidate Grant Doherty got 2.8 percent.

The message from voters, Buck said in his victory speech, was clear: “America has given us a two-year contract, and we better get this right. We better lead boldly. We better lead by inspiring. We better make sure that the plan that we have and the bills that we pass are the kinds of things all Americans can get behind and improve this country.”

Recalling that his parents were members of the World War II-era “Greatest Generation,” Buck said that they “never, never would have believed that the NSA would be spying on Americans, that the IRS would be discriminating against Americans, that the Department of Education would be forcing Common Core down our throats, that we have a president who won’t stand up for our interests in the Middle East and around the world.”

Quickly listing his prescriptions to correct the “wrong turn” he said America has taken, Buck said, “We need to flatten the tax code, and we need to shut the doors of the IRS. We need to make sure that nobody, ever again, messes with our gun rights. Do you hear that?” he asked, and the crowd roared its approval. “We need to make sure that this is such a business-friendly environment that all those corporations that thought it was cool to set up shop in some other country come running back and beg to be American corporations again.”

In a race that Democrats — and even some Republicans — expected to be closer, Lamborn defeated Democrat Irv Halter, a retired Air Force major general, 59.8 percent to 40.2 percent to win a fifth term in the 5th Congressional District.

Although the district leans heavily Republican — and has never elected a Democrat — state and national Democrats pegged the 5th CD as a race to watch, particularly after Lamborn only narrowly survived an unexpected primary against Bentley Rayburn, another retired Air Force major general. Then, in late September, the incumbent came under attack for remarks he made to a group of voters urging military officers to resign “in a blaze of glory” over disagreements with White House policy.

DeGette, the dean of the state congressional delegation, easily won a 10th term in the overwhelmingly Democratic 1st Congressional District, cruising to victory with 67.7 percent of the vote. Republican Martin Walsh has 29.2 percent, Libertarian Frank Atwood had 3.3 percent and unaffiliated candidate Danny Stroud, who was the GOP nominee in the last election, got 1.9 percent.

Polis won a fourth term in the 2nd Congressional District, defeating Republican George Leing, 56.5 percent to 43.5 percent.

Voters in the 3rd Congressional District sent Tipton back for a third term with 58 percent of the vote. Democratic nominee former state Sen. Abel Tapia, D-Pueblo, got 35.8 percent, Libertarian Travis Mero got 2.3 percent and unaffiliated candidate Tisha Casida got 3.9 percent in the district, which covers the Western Slope and southern Front Range.

Perlmutter faced a somewhat closer race than he has in recent elections, defeating Republican Don Ytterberg 55 percent to 45 percent in the suburban 7th Congressional District to win a fifth term in Congress.

But it was the Coffman-Romanoff contest that perhaps caused the most head scratching — precisely because, when the votes were counted, it wasn’t even close.

The star Democratic candidate — Coffman missed no opportunity to tag Romanoff the “top recruit” of former House Speaker Nancy Pelosi — proved to have some prominent targets on his back and was subject to a nearly constant barrage of TV ads saddling him with what Republicans called the biggest tax increase in Colorado history (omitting that GOP Gov. Bill Owens was equally responsible for pushing the bipartisan Referendum C measure, approved by voters) and tagging the Democrat as “dishonest” and “sleazy,” adjectives left over from his 2010 primary campaign against U.S. Sen. Michael Bennet.

Romanoff and outside groups supporting him attacked Coffman for his positions on reproductive rights and as a creature of Washington.

Coffman won by just 2 points in the last election against an unknown and underfunded Democratic challenger, and Romanoff raised more money than any congressional challenger in the country this cycle — despite refusing to take PAC contributions — and boasted that his campaign, under way since February 2013, had built “the largest grassroots operation in any congressional district in America.”

What the challenger hadn’t counted on — and what Republicans hoped would stay under the radar until election night — was an equally robust grassroots organization built by Coffman, along with leveraging the power of incumbency and using the latest digital technology to reach voters efficiently, his campaign said.

Coffman’s campaign manager, Tyler Sandberg, said even the Coffman campaign team was surprised by the 9-point margin over Romanoff, but that they weren’t surprised one bit by who won.

Sandberg credited Coffman’s willingness to reach out across the diverse district — including learning enough Spanish to phone undecided voters and participate in an historic debate conducted entirely in Spanish in the week before the election — with hardening support for the incumbent and with tapping votes Republicans often ignore and Democrats take for granted.

“You need to reach out to all communities,” Sandberg said two days after the election. “There is no vote that is unwinnable.” That effort included vigorous constituent service and proactive assistance throughout the community, such as bringing together various players to help the district’s immigrant populations from Africa, Asia and the Americas.

“When people see you care, that matters more than your party label or your ideology,” Sandberg said. “They want someone who can fight for them.”

All the outreach in the world wouldn’t have mattered if the Republican had been swamped by the Democratic ground game, but Sandberg said that the Coffman campaign’s canvassing and voter turnout machine was second to none.

In particular, he said, the campaign made it a priority to keep it personalized, including handwritten notes from Coffman and hand-addressed letters that went out to every targeted voter who had skipped the last midterm election, delivered on the same day that ballots arrived in the mail. In addition, Coffman himself spent hundreds of hours making thousands of phone calls to undecided voters this year — often having to get past skepticism that it was really the congressman on the phone.

The third leg of the stool, Sandberg said, was a sophisticated use of fresh digital technology, allowing the campaign to target specific voters with videos at a tiny fraction of the cost of broadcast media.

For instance, he said, when the Romanoff campaign blanketed the airwaves with an attack ad on abortion, the Coffman campaign delivered its response — which had already been written “and in the can,” Sandberg said with a chuckle — directly to the district voters who had seen the Romanoff ad, using set-top box data.

The Democratic turnout machine used similar tactics — it was hard to spend much time talking with organizers from either party without hearing the phrase “micro-targeting” — but the difference this year, Sandberg noted, was that Republicans gave as good as they got.

After all that outreach and after winning support from throughout the district, Coffman made a point of acknowledging the opposition in his victory speech on Tuesday night.

“To those who did not support me,” Coffman said, “I pledge to listen to your concerns and to do everything I can to bridge the partisan divide that has plagued Washington, D.C., and polarized this nation.”

See the Nov. 7 print edition for full photo coverage.

— Ernest@coloradostatesman.com