Kevin Stitt has found himself in a tight reelection contest despite the state's overwhelmingly conservative leaning with national Republicans investing millions of dollars in the race.
Stitt, who easily defeated former Democratic state Attorney General Drew Edmondson in that year's gubernatorial election, is in a close race with the state's top education official.
Hofmeister, a former Republican who switched to the Democratic Party last year, is gaining on the governor in some polls.
The Republican Governors Association is leading a seven figure advertisement buy to boost the incumbent governor.
Stitt, who has governed as a conservative in the deep-red state that overwhelmingly backed former President Donald Trump, has faced a lot of advertisements over his record in office.
More than $7 million in advertisements have been reserved by groups to either criticize Stitt's positions or support Hofmeister's candidacy, according to Ad Impact.
Hofmeister's campaign has spent $1 million on advertisements.
In a rare occurrence, the state's five largest Native American tribes threw their support behind Hofmeister.
"When it comes to working with the tribal nations in Oklahoma, she understands our sovereignty is not a partisan issue or a threat, but instead is a chance to forge new partnerships while strengthening those that already exist," the tribes said in a statement. This year's Oklahoma gubernatorial election is the most important in generations for all Oklahomans and that's why leaders of the Five Tribes are endorsing Joy Hofmeister to be Oklahoma's 29th Governor.
Stitt is a citizen of the Cherokee nation, but he clashed with the tribe over his plan to increase the fees they paid to run their casinos.
The governor pointed to the tribes as the source of the advertisements.
The casino bosses are large. He said that it was the big tribes.
There should be confidence in the state's rule of law, with potential crimes being prosecuted without any additional requirements posed by tribal sovereignty, according to Stitt.
She rejected the governor's strategy and said she would demonstrate independence and accused him of running through a national script.