Senator Brian Schatz waves to voters as they leave the poll in a special election held for two precincts that were not able to open because of Hurricane Iselle, in Pahoa, Hawaii, on Friday, Aug. 15. (European Pressphoto Agency)

Sen. Brian Schatz (D-Hawaii) won a closely watched primary on Friday, nearly a week after most votes were cast, turning back an intense challenge from Rep. Colleen Hanabusa (D) in the state's most pivotal intra-party fight in a generation.

The race was decided six days after voters first went to the polls. Damage from Tropical Storm Iselle prevented residents of two Big Island precincts from casting ballots during last Saturday's primary. State election officials opted for a make-up election there on Friday.

Schatz's win caps an intense and deeply personal campaign spanning more than a year. It was the latest clash between two competing wings of the state Democratic Party: a liberal, younger, whiter coalition represented by Schatz, and an older, more conservative, more Asian American contingent that held up Hanabusa as its standard-bearer.

The Associated Press called the race for Schatz on Friday night.

After last Saturday's vote, Schatz led Hanabusa by 1,635 votes, leaving the outcome in doubt and bringing lots of attention attention to the Puna precincts where voting was canceled. Both candidates rushed to the area to assist with storm recovery efforts.

Schatz padded his advantage on Friday, finishing ahead of Hanabusa by 1,769 votes out of a statewide total of more than 237,000 ballots cast.

Election officials initially said they would complete the vote by using absentee ballots. But later, they changed course and set the in-person vote for Friday.

Hanabusa objected, filing a legal challenge. She argued that voters were not given enough time to recover from Iselle. But a judge rejected her challenge on Thursday.

Schatz was appointed to the Senate by Gov. Neil Abercrombie (D) in December 2012 to fill the seat of late senator Daniel K. Inouye (D), a Hawaii political icon. Inouye had reportedly wanted Hanabusa, his political protege, to succeed him. Abercrombie's decision not to grant his wish sparked outage among the late senator's allies. Hanabusa joined the race in the spring of 2013.

Schatz will be heavily favored to win the general election against Republican businessman Cam Cavasso, given Hawaii's long tradition of electing Democrats. If he does, he will serve out the final two years of Inouye's term and face reelection in 2016.

In the campaign, Schatz cast himself as a more liberal candidate than Hanabusa. He also emphasized the relationships he formed with Democratic leaders during his year and a half in Washington. Schatz distanced himself from Abercormbie, who is unpopular and lost his own primary by a wide margin. Before his Senate appointment, Schatz was lieutenant governor under Abercrombie.

Schatz scored a major victory in late March when President Obama endorsed him. While Obama's image has deteriorated in many states, he remains a powerful political force in Hawaii, a deeply liberal state where he grew up. Schatz was an early backer of Obama against Hillary Rodham Clinton in the 2008 presidential campaign. Hanabusa backed Clinton.

The senator outspent Hanabusa by about $1.5 million through late July. He  was backed by leading environmental groups that spent money to help him win. Women's groups, including the pro-abortion rights organization Emily's List, supported Hanabusa.

Schatz's expected return to the Senate is a boost for the chamber's liberal wing. He tied Sens. Chris Murphy (D-Conn.) and Charles E. Schumer (D-N.Y.) for the title of most liberal senator in 2013, according to National Journal's vote ratings.