Corrections & Clarifications: A previous version of this story incorrectly stated Steve Weichert’s career background. It has been updated to remove the incorrect information.

Democrats think they can flip control of at least one chamber in the GOP-dominated Arizona Legislature this November, and they've set their sights on the state Senate.

Republicans currently hold a 17-13 majority there.

Democrats say support for #RedForEd, the teacher movement demanding increased funding for education, and opposition to President Donald Trump could boost their fortunes in the Nov. 6 election.

They are optimistic they can flip three seats to seize control — or at least two seats to achieve an even split in the 30-member chamber.

READ MORE: Is Trump reluctant to visit AZ before election?

The odds are less favorable in the state House of Representatives, where the GOP holds a 35-25 majority, though Democrats also look to pick up seats there.

Democrats haven't had a majority in either chamber for almost three decades. They last held power in the Senate in 1991-1992, and the chamber was evenly split in 2001-2002. They haven't controlled the House since 1966.

Here are seven key battleground districts to watch in 2018's battle for control of the Arizona Senate.

District 6: Sylvia Allen vs. Wade Carlisle in big area from Flagstaff to Payson

Will the third time be the charm for Democrats eager to topple Sen. Sylvia Allen?

Allen, R-Snowflake, has been targeted before and survived close races for her seat in District 6, which spans mountain communities: Payson, Flagstaff, Sedona and parts of Camp Verde.

This year, she faces a challenge from Wade Carlisle, the vice mayor of Holbrook.

The district has long been a GOP stronghold, particularly in rural towns where many longtime families, the descendants of Mormon pioneers, have deep roots. Allen hails from that stock.

But rapid growth in liberal-leaning areas has steadily transformed the voter base.

Flagstaff has boomed with development around Northern Arizona University, and deep-blue Sedona also has grown. Those trends have contributed to Allen's razor-thin victories in her last two contests.

Democrats are bullish that Carlisle is the right candidate for the rural district. He works on the railroad, ranches cattle and runs a hardware store.

Carlisle, also a substitute teacher, has made increasing funding for schools and road projects the centerpiece of his campaign.

Allen voted for teacher raises this year, but also has been a champion of private-school vouchers. She clashed with #RedForEd protesters at the Capitol, flashing a thumbs-down sign to the crowd during one tense floor debate.

She's also known for making controversial comments: In 2015, for example, Allen said it would be a good idea to make church attendance mandatory.

District 28: Kate Brophy McGee faces Christine Marsh in Phoenix race

One of the most closely watched races is in District 28, where incumbent Sen. Kate Brophy McGee, R-Phoenix, faces a spirited fight from teacher Christine Marsh.

The district spans areas of east/central Phoenix around the city's mountain preserves, including Arcadia, Biltmore, Sunnyslope and parts of Paradise Valley.

Brophy McGee has often been a key swing vote in the Senate, a moderate on bills related to education and health care. Republicans say her middle-of-the-road approach is a good fit for the centrist district.

But Marsh, a longtime high-school English teacher and Arizona's 2016 teacher of the year, argues Brophy McGee did little to stop years of deep cuts to education.

"Traveling the state ... I realized that I could not persuade our legislators to do what's best for kids," Marsh said during a recent debate. "So instead of changing their minds, we need to change them."

Democrats have blasted Brophy McGee for not getting behind previous bills they’ve introduced to increase accountability for charter schools, especially in light of The Arizona Republic's reporting about charter executives who have reaped millions in profits.

Those bills never got a hearing in the GOP-controlled Senate.

Brophy McGee this month called for overhauling charter-school laws to require that they comply with the same bidding and conflict-of-interest rules as district schools.

She has called herself the "education champion" in the race, and she's emphasized her role in persuading lawmakers to pass a 20-year extension of Proposition 301, the sales tax that helps fund schools.

"I'm a uniter, not a divider," Brophy McGee said at the debate. "I get things done, and I have the record to prove it ... More partisanship is not the solution."

District 21: Rick Gray vs. independent Kathy Knecht in northwest Valley

While Democrats and Republicans clamor for control of the Senate, an independent candidate could put either party's path to the majority in limbo.

Kathy Knecht, an independent, is challenging Republican Sen. Rick Gray for the Senate seat in District 21, which spans conservative bastions in the northwest Valley, including Sun City, El Mirage and parts of Peoria and Surprise.

She isn't the only independent to run for the Legislature, but unlike other nonpartisan candidates on the ballot this year, her campaign is formidable.

Knecht is well-known in the district: She has been a member of the Peoria Unified School District governing board since 2007, and previously ran Leadership West, a West Valley civic-advocacy group.

If elected, her vote could play an outsize role in selecting the chamber's next president. Knecht said she hasn't decided which party she would caucus with at the Capitol.

"My ideal would be to be able to work with both sides," she told The Republic. "No independent has gone before me to demonstrate how it would work."

Gray is also an established leader in the West Valley. He previously served six years in the House and was appointed to the Senate seat earlier this year, after Debbie Lesko resigned to run for Congress.

He questions if Knecht would truly be an independent voice in the Legislature.

"Everything she's doing, and the group's she's associating with, it's the Democrats," Gray said. "She's never really done anything with Republicans ... Voters just need to be informed."

Knecht's chief criticism of the incumbent has focused on education. She contends Gray has done nothing to stop years of Republicans' cuts to district schools.

Meanwhile, Gray counters, Republicans approved a budget with large spending increases for education this year. He said he's focused on specific solutions "not just rhetoric."

District 17: J.D. Mesnard takes on Steve Weichert in Chandler/Gilbert race

Another key target for Democrats is District 17, where current Speaker of the House J.D. Mesnard, who is termed out after eight years in that chamber, is running for the Senate.

Mesnard, R-Chandler, faces a challenge from Democrat Steve Weichert, a hospital administrator.

District 17 spans much of Chandler, parts of Gilbert and stretches south to Sun Lakes. The area has been solidly Republican, but Democrats predict support for the #RedForEd movement could provide them an inroad.

The race will be a key test of Democrats' momentum in suburban areas, where support for #RedForEd and apprehensions about President Trump have Republicans worried.

Weichert's campaign has focused on education. He accuses Mesnard of spending his "entire career chipping away" at district schools.

“He has a horrendous track record of reducing investments in public education, favoring private and charter schools, and eliminating financial transparency in the private and charter school system," Weichert said in an email.

Weichert ran for the same seat in 2016 and lost handily to current Senate President Steve Yarbrough, who's retiring from office. Now, he hopes to topple Mesnard, who aspires to be the next Senate president.

The race will likely be another uphill fight for Democrats given Mesnard has far out-raised his opponent and has high name recognition.

Mesnard has emphasized his role in sponsoring the GOP's plan to increase teacher pay 20 percent over three years (though some districts will give smaller or larger raises given funding is based on average pay).

"The talented individuals who work in the classroom are often underappreciated, and underpaid," Mesnard states in his campaign platform. "This should not be."

District 18: Sean Bowie and Frank Schmuck battle for Ahwatukee

If Democrats hope to win the majority in the Senate — or narrow the gap with Republicans — they need to hold onto their existing turf.

But Democrats have just one incumbent who's running in a key battleground district this fall: Sen. Sean Bowie, D-Ahwatukee Foothills, who represents District 18.

Bowie faces a rematch with Republican Frank Schmuck, an Air Force veteran and commercial pilot, who lost the 2016 election by a mere 3 percentage points.

District 18 spans Ahwatukee and parts of Chandler and Tempe. Republicans have held the area in the past, but that grip slipped in 2016 when Democrats captured a Senate and House seat.

Bowie has been careful to maintain his moderate track record while in office, often to the chagrin of liberal-leaning activist groups.

For example, he was one of four Democrats in the Legislature who voted for Gov. Doug Ducey's teacher pay-raise plan, though he said the proposal didn't go far enough to restore school funding.

District 8: Frank Pratt faces challenge from Sharon Girard in Pinal County

Pinal County was once a stronghold for Democrats, who had a base of support among the area's longtime Hispanic farming communities.

But District 8, encompassing much of the county, has turned increasingly red. The district spans mining towns Superior and Globe and exurban communities such as Casa Grande and San Tan Valley.

Sen. Frank Pratt, R-Casa Grande, took the seat for Republicans in 2016, defeating an incumbent Democratic senator. Pratt previously served eight years in the House.

Democrats hope Sharon Girard, a retired physician's assistant and activist for women's reproductive rights, can reclaim the seat. She has focused on improving access to health care for the uninsured.

The district has more registered independents than Democrats or Republicans, but GOP strategists say rapid growth in exurban areas will continue to give them the advantage.

District 20: Paul Boyer, Douglas Ervin and Doug Quelland seek north Phoenix seat

District 20, which spans parts of north Phoenix and Glendale, has drawn less attention than other battleground contests this year.

But both parties say the Republican-leaning district could offer an upset. Similar to other suburban areas, the #RedForEd movement has a following in the district, posing a potential challenge for the GOP.

Rep. Paul Boyer, R-Phoenix, is switching chambers to run for the Senate. He faces Democrat Douglas Ervin, an accountant; and Doug "Q" Quelland, a former lawmaker and independent.

The district's incumbent Sen. Kimberly Yee, R-Phoenix, isn't seeking another term because she's running for state treasurer.

Reach the reporter at dustin.gardiner@arizonarepublic.com or 602-444-2471. Follow him on Twitter: @dustingardiner.