Unlike Republicans, Democrats have had few opportunities this year to see any ideological splits among their candidates first-hand.

The exception is Hawaii.

Incumbent Sen. Brian Schatz has faced a rigorous challenge from Rep. Colleen Hanabusa in the Democratic primary. When the candidates met for a debate Monday, their discussion laid bare the divisions -- and areas of agreement -- between progressives and centrists in the party.

Here's what we learned:

The party is ready for Hillary

Or, if it isn't, Democrats aren't ready to say otherwise.

Hanabusa endorsed Clinton in 2008 in Hawaii's Democratic primary, and she did so again — and heartily — when the topic was raised during the debate Monday.

"I felt then that she would be a great president, and I feel now that she would be a great president," Hanabusa said. "I think that Hillary Clinton has paid her dues like no one else."

Schatz was positive, saying he hopes Clinton will run, but he nevertheless stopped short of any endorsement.

"I’m not going to get ahead of myself," he said. "The only election I’m thinking about is on Aug. 9."

Schatz added that his son said he hoped a woman would run for president -- but there are other Democratic women, such as Sen. Elizabeth Warren, who are thought to be potential contenders for the presidency. Warren has endorsed Schatz over Hanabusa.

President Obama's popularity is even flagging in Hawaii

With his approval rating in the low 40s, President Obama has so far this election been ducked by vulnerable Democratic candidates and only tacitly acknowledged by relatively strong ones. But, in Hawaii, the hometown hero still enjoys robust popularity -- for the most part.

When asked to rate the president's performance, Schatz, who led Obama's Hawaii campaign during the Democratic primary in 2008, called him a "very strong president."

"I'm proud to stand shoulder to shoulder with him," Schatz said. "I'm proud to have his endorsement. I'm proud to be one of his staunchest allies in the Senate."

But Hanabusa was less effusive in her praise, calling into question how Obama has handled crises abroad.

"There is no question President Obama is one of us," she said. However, she added: "Where I have parted with the president is the issue of Syria and Iraq. ... I believe that he has to explain to the people why he is potentially putting us into another war in Iraq, a sectarian civil war."

Democrats still aren't sure about marijuana

Medical marijuana is legal in Hawaii, and the Hawaii legislature recently considered decriminalizing small quantities of the drug, but fell short. Full legalization enjoys support from the majority of Hawaiians.

But even Hawaii Democrats aren't yet fully pro-pot.

Schatz and Hanabusa agreed that states should lead the way on crafting policies, a position that has been echoed by the party's leaders nationally.

"States are the laboratory of democracy, and democracy is occurring when it comes to this issue," Schatz said. "I don’t think Hawaii is ready for it; I don’t think we’re ready for nationwide legislation."

The two candidates diverged, however, on the extent to which the federal government should get involved.

Hanabusa suggested the federal government should put in place "a law or a policy not to interfere with whatever the state and its legislature and its people determine is in their own best interest."

But Schatz proposed only a national "conversation" about the merits of jail time for offenders, calling the current system "rigged against young men and women for nonviolent drug possession."

The issue of student loans has staying power

The growing burden of student loans has been invoked regularly by Democratic candidates in this election cycle, and might be an important theme moving forward for the party.

It's "the middle-class issue of our times," Schatz said.

"Higher education should be a ladder up economically," Schatz said. "Higher education is supposed to be part of the American Dream, and people are being priced out of it."

Schatz has worked with Warren in the Senate to promote student-loan forgiveness. The issue has been a signature of Warren's as part of a larger stump-speech theme of economic fairness.

Some of the starkest divisions are on less-buzzy issues

Whether to label genetically modified foods, for example.

GMO-labeling is a particularly hot-button issue in Hawaii, where seed crops comprise an industry worth hundreds of millions of dollars — but where some counties have sought to ban genetically manipulated agriculture.

Hanabusa played directly to the local-economic angle when asked for her stance.

“I do not believe GMOs are unhealthy and I stand with the farmers on that,” Hanabusa said. “And I also believe in the science that we have on GMOs.”

But Schatz, perhaps hewing to progressive support for organic produce, said states should lead the way in crafting policy.