Underneath all the confidence, all the promises of unity come November, many Democrats privately worry that they are understating the political risks confronting their party.

Two of their largest personalities — Honolulu Mayor Mufi Hannemann and former congressman Neil Abercrombie — are locked in a primary for governor that could be among the most expensive and divisive in state history.

Two of their most capable legislators — state Senate President Colleen Hanabusa and former congressman Ed Case — are stuck in a primary for Congress that could sap their resources and expose their weaknesses.

Waiting in November will likely be well-funded and polished Republicans — Lt. Gov. James "Duke" Aiona in the governor's race, and U.S. Rep. Charles Djou in urban Honolulu's 1st Congressional District — who will contend that Hawai'i needs balance to Democratic rule.

The anti-establishment mood on the Mainland may not have fully reached the Islands, but many Democrats believe it does exist, and that it may be a stretch for majority Democrats to cast themselves as the party of change even after eight years under Gov. Linda Lingle.

"This is going to be one of those times when it will really, I think, call us to task in terms of being Democrats, and our beliefs, and who we really are and what we stand for," said Alex Santiago, a former Democratic Party of Hawai'i chairman who is among hundreds of Democrats who have gathered this weekend for the party's state convention at the Hilton Hawaiian Village in Waikīkī.

"And I actually hope that, at the end of the day, we will be stronger."

THE RIFT ZONES

Republicans — and to some extent, the moderate Case — are trying to depict the party as a machine that has controlled Hawai'i politics since statehood. The truth is that the party is more like a collection of interrelated factions, with U.S. Sen. Daniel K. Inouye, the state's leading Democrat, as the connecting force.

While the party can function as a machine — as it did against Case when he ran against U.S. Sen. Daniel K. Akaka in the Democratic primary for Senate in 2006 — the contested primaries this year reveal the internal rifts.

Inouye, Akaka and the party's allies in labor have endorsed Hanabusa for Congress, again isolating Case. Inouye encouraged Hannemann to run for governor, but labor is much more splintered, with many union leaders behind the liberal Abercrombie.

Democrats are more confident about unity after the governor's primary than they are about the congressional race. Abercrombie and Hannemann would likely have to go nuclear against each other to push a significant number of moderate Democrats and independents to Aiona or to the sidelines in November.

But Democrats have not had such a competitive primary for governor involving two heavyweights in decades. The closest comparisons may be the primary between Lt. Gov. John Waihee and former congressman Cec Heftel in 1986, or even between Gov. John Burns and Lt. Gov. Thomas Gill in 1970.

"You have two strong guys who are not used to being pushed around. They are used to pushing other people around," one influential Democrat said privately.

"They are going to fight and scratch and try to bite each other's heads off and spit them out in the middle of the ring. But, in the end, Democrats will come together."

NOVEMBER TIPPING POINTS

Democrats are less sure about what happens after the Hanabusa and Case primary for Congress. If Hanabusa wins, a share of the independent and moderate voters who prefer Case may either back Djou or stay home, particularly if they believe that traditional Democrats treated Case poorly during the campaign. If Case wins, most of Hanabusa's voters will likely go with Case out of party loyalty rather than cross over for a Republican.

In 2006, Democrats did unite after difficult primaries between Akaka and Case for Senate and among the 10 prominent Democrats who ran for an open 2nd Congressional District seat won by Mazie Hirono.

But neither Akaka nor Hirono had to deal with the caliber of opposition that Djou, an incumbent, will present in November.

This year's primary may more closely resemble the Abercrombie and Hannemann fight for Congress in 1986, which was so bitter that Republican Pat Saiki took the general election.

"I really believe that the Democrats know how much is at stake, especially in Congress, and the importance of supporting President Obama and making sure that the Democratic agenda, the things that we believe in, that we have worked so hard for, are protected," said Jadine Nielsen of the Democratic National Committee.

Doug Pyle, a party activist involved in labor and economic issues, believes Democrats are offering voters real choices in the primaries and will be able to quickly come together against Republicans in November, particularly in the governor's race.

"We've just had eight years of what it's like to have a Republican governor," he said. "We've had a disaster economically, in terms of the budget, in terms of the stewardship of our schools."

REPUBLICAN CHALLENGE

Neal Milner, a University of Hawai'i-Mānoa political science professor, said Democrats have historically benefited from the relative lack of strong Republican opposition.

"The Democrats have had the luxury for so long of having a big cushion," he said. "They could do a lot of things wrong, as long as Republicans didn't put up good candidates."

But when Republicans have had credible candidates — such as Saiki, Lingle and Djou — Democrats have had trouble.

Randy Perreira, the executive director of the Hawaii Government Employees Association, said he hopes Democrats keep November in mind as they approach the primaries.

"There's no certainty. We're concerned about hard feelings being developed if there is a very tough primary campaign," he said. "But we all have to keep our eye on the bigger prize, and hopefully people will do that."