HELENA, Mont. — Montana Gov. Steve Bullock and Republican challenger Greg Gianforte are ratcheting up their campaigns and their rhetoric with early voting underway, as they change their focus from trying to sway undecided voters to rallying their supporters to cast their votes.

By the time Election Day arrives Nov. 8, most Montana voters will have already cast their ballots, if this year follows the pattern of the past three election cycles. The secretary of state’s office last week mailed out 297,000 absentee ballots.

Gianforte, a political newcomer who sold his software company RightNow Technologies to Oracle in 2011 for $1.8 billion, has flooded the airwaves with ads touting his business background and promising to bring high-paying jobs to the state. Last week, he made several get-out-the-vote appearances with other Republican statewide candidates.

Gianforte has pledged to roll back government regulations and to lower taxes for both businesses and individuals, while knocking Bullock as a career politician who has mismanaged the state. He has spent $3.1 million of his own money to get his message out.

“I believe firmly that jobs and opportunity, which is the No. 1 need we have, only gets created in the private sector by entrepreneurs, so we’re going to focus on making it easier for Montanans to start and grow businesses,” Gianforte said in a recent interview from his Bozeman home.

Bullock said he trusts voters to judge him by the record of his first term and his plans for a second. His campaign has focused mainly on making Bullock look gubernatorial, and his official schedule is packed with public appearances across the state on a variety of issues.

His campaign staff, meanwhile, has portrayed Gianforte as an out-of-touch millionaire seeking to buy the election and whose tax cuts would hurt the state.

“Montanans have seen how I can bring people together. Montanans have seen where we can make investments, and I think it will go to what kind of Montana do we want to see for the future,” Bullock said in an interview from the governor’s residence in Helena.

Ted Dunlap, the Libertarian Party candidate, is considered a long shot in the race.

Democrats have had trouble winning governor’s races during midterm elections, when turnout among the party faithful is lower in comparison to presidential elections, said Carroll College political science professor Jeremy Johnson.

Bullock has the advantage of incumbency and of the race being held during a presidential election — one of 12 governor’s races this year, Johnson said.

“Bullock is a popular incumbent governor and has successfully weathered criticisms of his record,” Johnson said.

Gianforte has tried hard to pick apart that record. The businessman accused the governor of aligning himself with environmentalists whose lawsuits could damage Montana’s oil and coal industries. He also criticized Bullock for not pushing hard enough against federal regulations.

Those regulations over water, air quality and animal protection threaten individual property rights, natural resource production and jobs, Gianforte said.

Anybody who says federal regulations are the source of the problems is trying to scare voters, Bullock countered. The energy downturn is a product of global markets, and a governor’s real job is uniting people to figure out how to move forward, Bullock said.

It’s about taking action, not just saying “I’ll shout at Washington,” Bullock said.

Another major difference between the candidates is their tax plans. Gianforte wants to eventually eliminate the business equipment tax for companies and lower the tax rate for most individuals, offsetting the revenue loss by slowing government’s growth.

Bullock noted the business equipment tax previously was eliminated for all but the largest companies. Gianforte’s tax cuts would threaten state funding for basic services, he said.

“This has happened all across the country where they’ve gutted things like public education or higher education or the bond rating,” Bullock said. “I don’t think that’s the way to go.”

Gianforte disputed that his cuts would affect services and said Bullock has mismanaged the state budget. Revenues this year have fallen short of projections when the last budget was written in 2015. The state’s finances are still in the black, but its rainy day fund is projected to drop to below $120 million by next summer.

“That’s the legacy of Steve Bullock,” Gianforte said. “We already have a financial mess in this state, and I’m proposing we fix it.”