Alaskans went to the polls in primaries Tuesday to narrow down a broad field of prospective office-seekers -- in races largely overshadowed by an oil-tax referendum which may affect the state for generations.

Ballot Measure 1, a proposed repeal of Gov. Sean Parnell’s Senate Bill 21 passed by the state Legislature last year, occupied an entire side of Tuesday’s primary ballots. Interest in the topic, which backers say could cost the state billions in tax revenue but opponents say jeopardizes Alaska’s competitiveness as a site for oil exploration, was reflected by standing-room attendance of a Loussac Library debate last month.

Initial returns, as of 12:20 a.m. Wednesday with about 80 percent of precincts reporting, showed Ballot Measure 1 behind by a margin of 5,894 votes with 74,474 no votes to 68,580 yes votes. That latest point sharpens a downward decline for the measure, which began the evening ahead by as much as 686 votes but fell to 1,067 votes behind at 10:30 p.m. 2,066 votes behind at 11 p.m. and 3,360 votes behind at 11:30 p.m. and 5,044 votes at midnight.

State Sen. Bill Wielechowski (D-Anchorage), one of the main proponents of Ballot Measure 1 and a participant in the Loussac Library debate, told Channel 2's Steve Mac Donald Tuesday night that while the issue wasn't decided, it was an important conversation for Alaskans to hold.

"Either way, this was a great debate for the state to have and either way, we'll have to wake up and get along in the morning," Wielechowski said.

Opponents of Ballot Measure 1 didn't turn out to speak with reporters about Tuesday's returns.

Late Tuesday, Lt. Gov. Mead Treadwell conceded after spending much of the night in third place behind Joe Miller and former state attorney general Dan Sullivan in the night's three-way GOP Senate race. Miller, in the race's middle position, told supporters Tuesday night that he was waiting on absentee and questioned ballots before conceding.

Sullivan leads the race with 40 percent of the vote, to Miller's 32 percent and Treadwell's 24 percent. Last week, the three men met in a Channel 2-sponsored debate as they hoped to challenge Sen. Mark Begich for his seat in the Nov. 4 general elections.

Sullivan, who had gathered his supporters at the Fat Ptarmigan restaurant in Downtown Anchorage, spoke with them inside at about midnight Wednesday -- but media weren't allowed inside to hear his remarks.

2014 Alaska Primaries Bring Increased Interest, Importance to Polls

In high-profile Legislature primary races, Rep. Bill Stoltze (R-Chugiak) is looking to trade in for a state Senate seat, challenging Palmer Mayor DeLena Johnson for the reapportioned District F seat. Rep. Mia Costello is also running unopposed to take the Republican nomination for the Senate seat occupied by Hollis French, but vacated when French opted to run for lieutenant governor.

Stoltze is initially leading Johnson with roughly 70 percent of the vote to Johnson's 29 percent.

Other contested primary races include House District 1, where Greg Bringhurst has nearly 72 percent of the vote over Jomo Stewart's 27 percent, and House District 6, where David Talerico leads Thomas Dunning with nearly 70 percent of votes versus Dunning's 29 percent.

Doug Isaacson appears to be losing to Tammie Wilson, forced into the same primary for House District 3 by redistricting, with just 44 percent of the vote to Wilson's 55 percent.

A closely fought three-way GOP primary for House District 9 will likely see Rep. Eric Feige lose his seat, as Feige musters just 29 percent of the vote to George Rauscher's 34 percent of the vote and leader Jim Colver's 36 percent.

House District 12's GOP nominations will probably go to Cathy Tilton, who leads Ronald G. Arvin by roughly 65 percent to 34 percent.

In House District 16, Iron Dog snowmachine race director Kevin Kastner is behind Don Hadley, with 43 percent of the vote to Hadley's 56 percent.

House District 19 incumbent Rep. Geran Tarr easily fended off a challenge from libertarian Cean Stevens, securing 86 percent of the vote to Stevens' 13 percent.

House District 21, where Republicans Anand Dubey and Matt Fagnani have fought to succeed Democrat-turned-Republican Rep. Lindsey Holmes after her retirement, seems likely to have Dubey take the GOP nod. About 60 percent of the GOP vote is going for Dubey, versus Fagnani's nearly 39 percent.

Liz Vasquez might have an edge on the GOP nomination in House District 22, where she leads Sherri Jackson with nearly 51 percent of the vote to Jackson's roughly 49 percent.

A Kodiak dynasty seems unlikely to materialize in House District 32, where Louise Stutes is leading two opponents including Carol Austerman, daughter of longtime Rep. Alan Austerman, and Rich Walker. Stutes has control of the race with 44 percent of the vote, to Walker's 28 percent and Austerman's 26 percent.

Another three-way race, in House District 36, has Chere Klein taking 44 percent of the vote against opponents Agnes Moran and Patti Mackey, with 31 and 24 percent of the vote respectively.

The two contested Democratic seats -- House Districts 2 and 40 -- both appear to be landslides, with Larry Murakami leading Uriah Nalikak with almost 70 percent of the vote while Benny Nageak holds a commanding 90 percent of the vote against Dean Westlake.

In less competitive statewide races, Gov. Sean Parnell will have the chance to run for his seat again, garnering about 75 percent of the vote in his primary; Byron Mallott, the main Democratic challenger set to face him, has 65 percent of the Democratic vote.

Anchorage Mayor Dan Sullivan appears on track to take the Republican nod for lieutenant governor, leading Kelly Wolf with about 70 percent of the vote. His Democratic counterpart seems likely to be French, who has about 62 percent of the vote in his bid for the state's No. 2 executive position.

Begich also appears more than able to secure the Democratic nomination for his current position, receiving 83 percent of the vote against a field of half a dozen challengers. Rep. Don Young is also ably fending off challengers with nearly 74 percent of the vote, and appears set to face Democratic challenger Forrest Dunbar who is leading his field with roughly 62 percent of the vote.

Even from the outset polls were markedly more busy than usual, with the state Division of Elections reporting nearly 10,000 early and absentee ballots cast before Tuesday compared to about 5,100 in 2010.

Election workers at many Anchorage precincts reported about twice the traffic of a usual primary, with some voters finding themselves in line to receive a primary ballot for the first time in recent memory.

Polls were open across the state from 7 a.m. to 8 p.m. Tuesday.

Channel 2's Austin Baird and Corey Allen-Young contributed information to this story.

This is a developing story. Please check and the Channel 2 newscasts for updates.