With runoff elections less than a week away, the race for Oklahoma’s next governor is already shaping up to be one of the most expensive in state history, according to the candidates’ most recent campaign filings.

Thus far, the state’s gubernatorial candidates have spent a combined total of $15.8 million this election season. And that’s not counting more than $1 million spent in the governor’s race so far by non-candidate groups.

Meanwhile, some vulnerable incumbent legislators who were forced into a runoff after the June 26 primary election have begun to lag behind their challengers in fundraising, the most recent round of campaign filings show.

The runoff election is scheduled for Tuesday. The general election is scheduled for Nov. 6.

According to Oklahoma Ethics Commission records, during the 2010 governor’s race (the last governor’s race in which there was no incumbent running), candidates reported spending a combined $11.5 million during the entirety of that election year. Before that, during the 2002 election, candidates reported spending a total of around $10.7 million by the end of the year.

But while this year’s nearly $16 million spent even before the runoff is substantial compared to past races in the state, the nature of this year’s race and the increasing cost to run a campaign fits with broader national trends, said Keith Gaddie, professor of political science at the University of Oklahoma.

“That’s a chunk of change for a primary in Oklahoma,” Gaddie said. “Campaigns have been getting more expensive all around for everybody, and this is still the plumb nomination, so serious contenders went into it and spent large amounts of money just to make the runoff and they’ll do it again to win the nomination. So this is perfectly normal for what we see going on around the country, and we’ll get used to it here.”

During the June 26 gubernatorial primary, voters had 10 Republicans, three Libertarians and two Democrats to choose from. That too played a role in the amounts of money being dropped, Gaddie said.

“This is the most wide-open governor’s race we’ve had in quite some time, and the most wide-open Republican party primary we’ve had ever,” he said.

The only outright primary victory in the governor’s race was by Democrat Drew Edmondson, who will face the Republican and Libertarian winners of the runoff elections in November.

Edmondson has so far raised more than $1.9 million, including more than half a million dollars since June 12, and spent around $1.3 million, according to campaign records.

Meanwhile, Republicans Mick Cornett, former mayor of Oklahoma City, and Kevin Stitt, Tulsa mortgage company owner, have been slugging it out since the primary election.

Between June 12 and Aug. 20, Stitt’s campaign spent more than $2.2 million in advertising and other campaign operations, compared to Cornett’s $1.2 million spent during the same time period. However, at least two non-candidate groups — Oklahoma Values and The Foundation for Economic Prosperity — have also been working on Cornett’s behalf by purchasing ads attacking Stitt or endorsing Cornett. Records show those two groups have spent more than $860,000 since the primary election attacking Stitt.

During the entire election season this year, Stitt has spent more than any single candidate in any race in the state, including Congressional candidates, records show, with his expenditures topping $6 million since he entered. Cornett has spent about $2.8 million in total. For context, Gov. Mary Fallin spent about $4.3 million during the entire 2014 election season.

Campaign records show that Cornett and Stitt were able to raise around the same amount of monetary and in-kind donations since just before the primary — about $1.3 million by Cornett and $1.2 million by Stitt. However, Stitt also loaned his campaign an additional $1.1 million during that period, putting his total loans to his campaign at nearly $3.3 million.

Oklahoma gubernatorial candidates lending themselves money is not unheard of, though the amount loaned by Stitt thus far is likely among the highest. For example, during the 2010 gubernatorial race, Democrat candidate Jari Askins loaned her campaign a total of $1.1 million, and in 2002 Gary Richardson, who ran for governor as an independent that year, loaned his campaign about $2.3 million, according to a report by the Associated Press. Richardson disputes that amount, saying he loaned his campaign around $1.2 million in 2002. The Ethics Commission database does not show the amount of Richardson’s loans in 2002.

Gaddie cited former Gov. Brad Henry, who took out a mortgage on his home to loan his campaign around $374,000 during his first run for governor in 2002 as an example of candidates making loans to their campaign. More recently, President Donald Trump made substantial loans to his campaign during the 2016 race, he said.

“It’s not at all unusual to see candidates borrow and then their campaign pay them back later,” Gaddie said.

Other races are also seeing record amounts of money being spent already. Incumbent Attorney General Mike Hunter was forced into a runoff against challenger Gentner Drummond, a Tulsa attorney.

Drummond has thus far loaned his campaign $1.2 million, while Hunter has loaned his $700,000. And though a third Republican and Democrat Mark Myles have also spent money vying for the spot, Drummond’s and Hunter’s campaigns make up the overwhelming majority of the nearly $3.9 million spent in the race so far. In 2010, the year Scott Pruitt was elected Attorney General, candidates spent a combined total of about $2.3 million during the whole election season, Ethics Commission data shows.

Meanwhile, the most recent campaign filings by some sitting legislators from the Tulsa area who were forced into a runoff show that the rising tide of campaign money this season doesn’t necessarily lift all boats.

Incumbent legislator Rep. Mike Ritze, R-Broken Arrow, came in second during the House District 80 primary election to Tulsa firefighter Stan May, though neither had a majority of votes, resulting in the runoff.

Since then, Ritze, who is probably best known for his attempts to have a monument of the 10 Commandments placed at the state Capitol, has been endorsed by U.S. Sen. James Lankford and former Sen. Tom Coburn. Ritze faced backlash after he voted against tax increases to pay for teacher raises, as well as allegations that he embellished his military record.

Campaign filings by both Ritze and May show that since the primary, May has received about $25,000 in donations compared to Ritze’s $8,300. As of Aug. 20, Ritze had about $5,000 left in his campaign account, compared to May’s $30,290.

Incumbents already find themselves in perilous territory when they’re forced into a runoff election, Gaddie said, and only about a third survive. Add to that a candidate that has not had to campaign in nearly a decade, a political “tin ear” and an imbalance in where the money in the race is headed, and the odds are not in Ritze’s favor, Gaddie said.

“Mike’s got himself in a pickle. You don’t find incumbents coming out in second place to win. If he pulls it off, it’s defying every odd,” Gaddie said.

“This is the classic situation of the incumbent getting out of touch with the constituency,” Gaddie said, “taking a series of bad votes that the constituency disagrees with… getting into a runoff and then not understanding how to campaign his way out of it.”

Another incumbent forced into a runoff is Rep. Sean Roberts, R-Hominy, who will face former newspaper owner Louise Redcorn. The House District 36 runoff will decide the race, since no Democrat filed to run in the election.

Roberts has received about $11,600 in monetary donations since June 12, compared to nearly $28,000 raised by Redcorn.

Meanwhile, in Bartlesville’s House District 10, incumbent Travis Dunlap received only $145 more in donations since June 12 than challenger Judd Strom (Dunlap’s $14,605 to Strom’s $14,650), who he will face in the runoff Tuesday.

Both Roberts and Dunlap are receiving support from non-candidate groups in the form of advertising advocating for their re-election in their respective races.