U.S. Sen. Brian Schatz raised about $822,000 during the past quarter in the Democratic primary for Senate, sending his fundraising total over $4.8 million for the campaign.

The senator, who is facing U.S. Rep. Colleen Hanabusa in the primary, had his best fundraising quarter in the past year, according to a draft of his federal campaign-finance report.

Hanabusa, a spokesman said, will likely not release her quarterly figures until closer to the filing deadline on Tuesday. She had raised $2 million through March.

Schatz has maintained a 2-to-1 fundraising edge over the congresswoman and is using the money to dominate the airwaves in the weeks before the August primary. The Schatz campaign has spent $3.3 million so far.

"The Schatz people have run a very good campaign and they’ve made it more difficult for her to raise money," said John Hart, a communication professor at Hawaii Pacific University. "And money obviously means a lot in Senate races. But it’s also how you spend your money, how you make the media buys, how good are your commercials, et cetera, et cetera."

But Hart said it will be the debates between the two Democrats that might make the difference. Schatz and Hanabusa have had three debates — one on statewide television — and have two more televised debates scheduled next week.

"At the end of the day, this race, I think, was going to come down to the debates," Hart said. "And I still think that’s the case."

Hart said the question for him is how many voters are still undecided and might be influenced by debates or campaign ads.

Other political observers are more skeptical about the impact of debates, since voters who are the most likely to watch political debates often have already made up their minds or are leaning strongly toward one of the candidates.

Voters are more likely to have seen a candidate’s ads or to have read, listened to or watched news media accounts of the campaign.

"Close to 3,000 people in Hawaii have contributed to our campaign for Hawaii’s future," Schatz said in a statement about his fundraising. "It’s really exciting to have the support of so many families across the state as we work to get things done for Hawaii."