When lawmakers in Kansas considered legislation to regulate services such as Uber, the ride-hailing company sprang into action, urging local customers and drivers to blast legislators with e-mails opposing the bill.

But instead of persuading legislators to side with Uber, the campaign disrupted the state legislature's e-mail system — temporarily making it inaccessible and leaving frustrated lawmakers struggling to find important messages in a sea of more than 1,500 form e-mails from Uber customers.

"Every legislator got all the same e-mails," said state Sen. Marci Francisco (D), who voted for the bill. "And they weren't just from Kansas — some were from out of state. Maybe 20 were from my district."

Uber, which operates is more than 50 countries, has faced serious regulatory hurdles for years -- often for starting operations first, and worrying about local laws later. Last year, the San Francisco-based company hired David Plouffe, one of the architects of President Obama's 2008 election campaign, to wage the company's political battles and help bend local regulations in its favor. The scuffle in Kansas is part of an increasingly aggressive strategy by Uber that often leverages the loyalty of its users.

In Kansas, lawmakers passed the legislation Thursday night, days after Uber started its digital campaign. The company had criticized the bill, saying it contained a "poison pill" added in by "bank executives" and threatening to "cease all operations" in the state if it becomes law.

In one blog post, Uber asked local users to contact their lawmaker and included a button they could use to send an e-mail — but instead of helping constituents find their individual representatives, it sent messages to all 165 Kansas state senators and representatives. The company also e-mailed drivers and riders in the two areas where it operates in the state with the same request — and because the Kansas City market straddles the Missouri border, not all recipients were Kansas residents.

"We consider it our responsibility to notify users when regulators or elected officials are working to prevent them from a service they use everyday — either to get a ride or make a living," spokeswoman Jennifer Mullin said. "After notifying users in Kansas, many individuals chose to e-mail their elected officials to voice their support for keeping Uber in the state."

The campaign temporarily disrupted the legislature's e-mail system. Service was down for a few hours  Tuesday until the state made adjustments to its e-mail servers, said Thomas Day, director of Kansas legislative administrative services.

But state Sen. Tom Hawk (D), who voted for the bill although he is a fan of the idea behind the Uber app, said he was still unable to check his work e-mail from his smartphone a few days later. "I couldn't take care of any business," he said, "I think it was a tactical error on their part." In fact, the one message that stood out to Hawk was from a driver in Wichita who laid out concerns about how the company treats people who drive for it, he said.

The issue that drew Uber's ire is related to insurance coverage. Uber already provides its drivers insurance, but it is not comprehensive for the whole time that the drivers are working through the app — and when their personal insurance policy won't provide coverage. That leaves a potential gap for drivers who still have loans on their vehicles that require comprehensive coverage at all times. The legislation would require that drivers get an insurance rider to cover that gap.

That is more insurance coverage than is required in any other state and unfairly targets companies such as  Uber, Mullin said. "People have operated their private vehicles for business purposes for decades and never needed this level of insurance: pizza delivery, lawyers driving clients, healthcare workers with patients, etc. have never had to carry this level of insurance," she said in an e-mail.

State Sen. Jeff Longbine (R), who owns a car dealership in Emporia, Kan., said he had concerns about Uber's tactics leading up to the e-mail campaign.

When the final version of the bill was being worked out by the committee, he said, an Uber representative gave him an ultimatum: Unless the insurance provision was removed and other onerous regulatory requirements that might keep out less established competitors stayed, Uber would get its customers to wage a campaign that painted lawmakers as job-killers.

"Honestly, threats like that aren't taken very well in the legislature," he said.

Mullin said that she was unable to comment on the specific exchange because she was not present but that advocating for regulation that could restrict competitors would be counter to the company's values. "Uber advocates for opening up competition, not limiting it," she said.

Uber on Friday launched a petition asking Gov. Sam Brownback to veto the bill and maintains it will be "impossible for Uber to continue operating" in Kansas if he doesn't. The petition now has more than 6,200 signatures — 4,100 of which Uber says were collected within seven hours after the campaign was launched and the company sent an e-mail blast to "activate" drivers and customers in the markets where Uber operates in the state.

"The Kansas State Legislature just passed a bill — SB 117 — that would destroy thousands of Kansas jobs by making it impossible for Uber to continue operating here," the text of the petition reads.

Kansas is not a huge market for Uber, which operates in about 300 cities in 56 countries. But that also makes it the ideal place to test out hardball tactics and see how much pressure the company can exert on policy debates. Pulling out of Kansas over this particular insurance tweak may be worth it to Uber in the long run if it stops other states where the company operates from considering the same type of change.

And Uber has followed through on threats to leave other markets.

The company left Boise this year after a tense standoff with local leadership over the legality of its operations in the city. Uber then took the fight to the state legislature, where its local lobbyist proposed a bill that would allow the company to bypass regulations in the state. The bill became law Monday.

Last week, the company cut off service in San Antonio over a local ordinance it didn't like. But Uber hasn't abandoned the city. It's now urging users and drivers in the area to vote for candidates who will roll back the change in an upcoming local election. Uber is also asking users to support state-level legislation that would override local regulations — much like the Idaho law.

Both the Kansas and San Antonio situations hit at the heart of Uber's strategy: The company's most valuable political asset is its ability to rally drivers and customers to its defense. A driver or a customer might not understand the underlying policy questions at stake, but they probably will click a button in support of the service if it means continuing to have a cheap transportation alternative or a source of income.

"The magic of the Uber platform is that it makes connections: We connect riders to drivers, residents with their cities, and, sometimes, constituents with their elected officials," said Mullin, the Uber spokeswoman.