John Suthers, left, as Colorodao attorney general in 2011. Now mayor of Colorado Springs, Suthers has run into opposition from a conservative group over his proposal to raise the sales tax to improve roads. (Andrew Harrer/Bloomberg News)

This much everyone can agree on: The streets of this large city on the Rocky Mountain Front Range are a wreck. Sixty percent are in disrepair, cracked and rutted; driving on them is often a game of vehicular Minesweeper. One local TV news channel runs a segment called “Pothole Patrol.”

But when this city’s newly elected conservative mayor urged voters to approve an increase in the sales tax to pay to improve the roads, he drew fire from an un­expected source: a branch of Americans for Prosperity, a power­ful conservative advocacy group backed by the billionaire industrialists Charles and David Koch.

The group’s involvement in a municipal infrastructure issue spotlights how AFP is seizing on local issues across the country as it works to build a permanent grass-roots army.

The group helped derail a recent roads bill in South Carolina. It faced off with Wichita’s city council over an apartment development deal and with Milwaukee’s over a streetcar project. In Coralville, Iowa, the group pushed back on a tax increment financing plan. Near Denver, it was in the middle of the fierce fight for control of the Jefferson County school board.

And in Colorado Springs, it has taken on the road tax. The organization started an online petition and took out Facebook ads to oppose the tax. The group produced a 23-page report on the issue and even hired an out-of-state accountant to examine the city’s budget. In a City Hall presentation, the accountant told local leaders they should be able to find money to fix the roads without raising taxes.

Now nervous civic leaders wonder whether AFP will wade into the ballot initiative over the tax this fall.

Mayor John Suthers, a Republican and former Colorado attorney general, has been pushing hard for the 0.62 percent sales tax increase. “The money,” he told a group of business leaders at a town hall meeting last month, “would go to a separate fund to be used for roads only.”

Suthers has called AFP’s proposal “an incredibly uninformed analysis,” but he was reluctant to talk about the group in an interview with The Washington Post.

“To the extent they’re wrong, I’m going to say, ‘You’re wrong,’ ” Suthers said. “But I’m not going to get in a back-and-forth.”

Expanding at local level

Suthers, who took office this summer, said the tax increase would generate a projected $250 million in new revenue directed to repair the roads in Colorado’s second-largest city — a Republican stronghold that is home to five military installations and a network of churches that bloomed around the region when Focus on the Family moved here in the early 1990s.

Colorado Springs is also home to a chapter of AFP, the prime political arm of a nonprofit network backed by the Kochs and other conservative donors who have pledged to spend $889 million in the run-up to the 2016 elections.

Their ultimate impact on next year’s races is unknown. Their ability to influence policy at the local level is already apparent.

By mid-summer, a steadily expanding AFP, which has been active in Colorado for about six years, had offices in roughly three dozen states and counting, with a focus on permanently embedding hundreds of staffers at the state and local level. They have launched a swarm of campaigns to affect the outcome of local fights. Some of those efforts have involved battling Republicans. In Colorado Springs, it has meant taking on business leaders, and the conservative mayor.

Angela Dougan, a former City Council member, started the AFP chapter in Colorado Springs. She said AFP hasn’t decided whether to spend money in the official campaign over the tax question.

“We will be educating people,” she said of her group’s involvement on the tax plan.

However involved it is in the ultimate ballot battle, AFP’s profile on the issue already represents a new kind of politics for this city. “I’ve never seen this kind of coming-in-from-the-outside as is happening now,” said Mary Lou Makepeace, who was mayor from 1997 to 2003 and lost a comeback bid to Suthers this spring.

Kochs ‘may write a check’

Of course, deep-seated tax aversion isn’t an import in Colorado. Thanks to a 1992 constitutional amendment called the Taxpayer Bill of Rights, or TABOR, any tax increase at the state level requires voters’ approval. This fiscal straitjacket also applies to Colorado Springs, where the man who authored TABOR, a local landlord and anti-tax folk hero named Douglas Bruce, persuaded the city to put TABOR in its charter in 1991. Successful in Colorado Springs — Bruce calls his city “the epicenter of the tax revolt”— he took the effort statewide the next year.

In 2012, Bruce went to jail on charges that included tax evasion. He’s currently facing a hearing to determine whether he violated his parole, and he accuses the state’s political elite of trying to send him back to jail to snuff out another anti-tax crusade. Bruce has dubbed the mayor’s proposal in Colorado Springs a “pothole tax.” He has shown up at public meetings and bet members of the City Council $100 apiece that their tax hike will fail. (The council voted 8 to 1 to put the tax question to voters; only one of them took Bruce’s bet.)

Bruce’s 1991 effort in Colorado Springs was a homegrown operation. This time, he’s angling for heavy artillery.

“Because of what I did with the city and the state — TABOR— it’s sort of the home of tax limitation,” he said. “The Koch brothers, they may write a check.”

Jeff Crank, a former AFP state director who lives in Colorado Springs, said he’s already been able to raise hundreds of thousands of dollars to fight the tax, should he need it. He said he hopes the mayor and City Council will listen more closely to AFP’s suggestions about finding money for the roads without raising taxes.

“If they just ignore it and decide they aren’t going to take any of AFP’s advice, I think we will probably do much, much more,” Crank said.

Behind the scenes, more is already happening. Some city residents have been answering the phone to hear an electronic message posing as a poll that critiques the tax. Dougan said AFP is not behind the calls.

Last month, as Suthers headed for his car after a meeting, he did not want to talk about what it’s like to do battle with AFP as a newly elected mayor. There was no time for conversation with his first big initiative on the line.

“I’m trying to win this thing,” he said.

Hutchins is a freelance writer. Matea Gold contributed to this report.