The Arizona State Capitol could see a 15-15 split of state senators with the race still too close to call. (Photo by Emily Achondo/Cronkite News)

PHOENIX – Republicans have traditionally controlled both chambers of the state Legislature. Some experts wondered whether Tuesday’s election would put the 30-member state Senate in play, potentially shifting the balance of power.

Early results on Election Night indicated that Democrats stood a chance at splitting the Senate 15-15. Unofficial results on Wednesday suggested that’s not as likely. However, officials are still tallying ballots.

Rep. Ken Clark, D-Phoenix, said Tuesday night that he was optimistic: “We think we’ve really got a shot at a 15-15 Senate.”

Sixteen years ago, the Democrats managed to split the Senate, but the equity was short lived.

Mike Gardner, a lobbyist with the group Triadvocates, said this election season is different for the traditionally red state. One reason: The propositions. Proposition 205 asks voters to legalize recreational marijuana, and Proposition 206 would raise the minimum wage.

Both bring a new set of voters to the ballot box, Gardner said.

“Those issues are giving Democrats an excuse to show up,” he said.

“Another moving part we have this year is education, and the Democrat message is resonating really well here,” Gardner said.

Others who follow the state Legislature closely have similar opinions.

Arizona State Historian Marshall Trimble said he has noticed that voters who traditionally go red are getting fed up with Republican decision making on certain issues, such as education.

Trimble said that many moderate Republicans oppose continued cuts to education and that disagreements within the party over this issue have opened the door for Democrats who favor increased funding.

“People are a little tired of business as usual down at the state house. They are saying, ‘Let’s change things down there, we got to start taking a better look at education,'” Trimble said.

Republicans hold the current Senate majority with an 18-12 split. Some experts pointed to four key races that could have tipped that balance.

District 28: This east-central Phoenix/Paradise Valley race pits Republican Rep. Kate Brophy McGee against Democrat Rep. Eric Meyer for the Senate. Wednesday’s unofficial results still showed a tight race.

District 18: Comprised of Ahwatukee, Tempe and Chandler neighborhoods, District 18 has seen a surge in registered Democrats since 2014, according to data from the Secretary of State’s office, yet Democrats still trail Republicans and independents in the area. Independent voters, who now make up about a third of the district’s voters, may be the deciding factor. Republican Frank Schmuck is facing off against Democrat Sean Bowie. Unofficial results Wednesday indicated Bowie had a slight lead.

District 8: According to voter registration data from the Secretary of State, this district also has more registered independents than Democrats. It includes areas in Globe, Superior, Florence and Coolidge. Republican Frank Pratt of Casa Grande is going head to head with Democrat Sen. Barbara McGuire, D-Kearny. Unofficial results Wednesday indicated Pratt was leading.

District 6: This mostly rural district in eastern and northern Arizona includes Flagstaff and Show Low. Republican Sen. Sylvia Allen, R-Snowflake, is battling former Jerome Mayor Democrat Nicki Bagley. Unofficial results Wednesday showed Allen ahead in the race.

Democrats must win three of these four battles to split the Senate.

Gardner said it has been a while since he has seen races this close.

“There are more votes still in play,” he said Tuesday night. “Friday or Saturday at the best, most likely Monday, we will find out the winners of some of these races. It’s too close to call tonight.”

Eight incumbent senators are not running for re-election in 2016. Arizona senators serve two-year terms, with each representing one of the state’s 30 legislative districts.

Several House seats are up for grabs in the same battleground districts, but Republicans are expected to maintain a firm hold on that chamber.