(CNN)Democrats are pointing to closer-than-expected results of a House special election Tuesday as the latest evidence that this year's midterms will cement Arizona's status as a marquee swing state.
Democrats set sights on turning Arizona blue after special election result
In a West Valley district that President Donald Trump won by 21 percentage points, Democrat Hiral Tipirneni came just 5 points shy of upsetting Republican Debbie Lesko on Tuesday.
That swing follows a pattern of Democratic gains in statewide and special elections since last year. And if it continues through November, it could mean a sea change in Arizona, where Republicans are defending both retiring Sen. Jeff Flake's seat and Gov. Doug Ducey this fall.
"I was thinking if Hiral could make it a 10-point margin, that would be a victory. To make it 5 -- that is earthshaking," said state Sen. Steve Farley, a leading Democrat in the governor's race. "We are talking about every Republican office going Democrat in the next election if that margin holds up."
Tuesday's contest, more than a month after Democrat Conor Lamb narrowly won a deep-red House seat in the Pittsburgh area, was an opportunity for Democrats to test whether their momentum had spread across the map, and for the GOP to try to fix some of the problems that have plagued the party in recent contests.
The Arizona Democratic Party and Maricopa County Democrats spent two months casting the special election as a test run in a state that also includes several potentially competitive congressional seats. They launched the largest field operation Arizona's 8th District, west of Phoenix, has seen in years, with 465 volunteers knocking on nearly 60,000 doors, making more than 90,000 calls and sending more than 60,000 text messages.
"This special election showcased Democrats' enthusiasm and hard work to make every seat and every race competitive," Arizona Democratic chairwoman Felecia Rotellini said in a statement.
"Republicans have shown in this race that they are worried about their ability to elect candidates up and down the ticket in 2018 and beyond," she said.
Tipirneni's campaign focused on health care and defending Social Security and Medicare. Meanwhile, protests over education funding dominated the state's headlines, leading to a teacher walkout Wednesday and giving Democrats an opening to hammer Ducey and other Republicans on a local issue.
The landscape could look similar this fall for Rep. Kyrsten Sinema, the Democratic Senate hopeful.
She's awaiting the winner of a three-way August 28 primary between Rep. Martha McSally, the GOP establishment's preference, and two die-hard conservatives -- former state Sen. Kelli Ward and former Maricopa County sheriff Joe Arpaio.
Sinema tweeted that the results "show that Arizonans are fed up with the chaos in Washington. November is coming."
Republicans saw some reason for optimism in the Arizona results.
Most ballots there were cast early, and the GOP hit its early voting targets in part due to a cheap (at just $65,000) but effective digital advertising campaign by the consulting firm Cavalry LLC for the Congressional Leadership Fund super PAC.
The digital campaign resulted in more than 5 million impressions aimed at a narrow list of 100,000 Republican voters, meaning each voter saw ads, many of which focused on selling the GOP's tax cuts, on places like Facebook about 50 times.
There was also help from the top.
Trump placed a robo-call to Arizona Republicans urging them to vote early.
Arizona was an easy place to implement that strategy. The state has a "permanent" early voting list of people who have signed up to always receive early ballots. But Republicans said a similar approach could work in other states, too.
"There's no perfect silver bullet to a tough political environment," said Cavalry's Michael Duncan, who led the digital effort. "But Arizona shows that Republicans should invest in early voting and digital and not leave any votes on the table, that's for sure."
Democrats, meanwhile, were pleased with results in Arizona that they said underscored that the 2018 battleground map is continuing to expand.
"This shows momentum, it shows activity, it shows engagement beyond anything we've ever seen," said Charlie Kelly, the executive director of the House Majority PAC, a Democratic super PAC.
"And I think it speaks to the sort of challenge facing Republicans and the fact that they really don't have a plan for this other than to look inward at the agenda they push, which focuses exclusively on hurting middle-class families."
Kelly's group has already reserved $40 million in television air time across 33 congressional districts this fall, and he said more are being added to its list of potential targets every day.