HONOLULU (AP) _ Liberal incumbent Sen. Daniel Akaka held a strong lead Saturday night over upstart challenger Rep. Ed Case in Hawaii's Democratic primary.

Akaka was leading 54 percent to 45 percent with about two-thirds of the expected vote counted. He had 87,102 votes compared to Case's 71,712.

Who the winner faces in the general election remained a mystery after former Vietnam prisoner of war Jerry Coffee, who pulled out of the race because of health reasons, won the GOP nomination. Republicans have three days to name a replacement candidate.

Akaka, 82, has served in Congress for 30 years and drew on his experience to boost his candidacy.

``I want to thank Hawaii for supporting me all these years,'' he said, singing ``God Bless America'' after hearing the most recent results. ``It has been a tough campaign for me.''

Case, 53, who was running behind on all islands, did not concede the race. He had argued that Hawaii needs a younger, more moderate senator.

Case faced the difficult challenge of unseating Akaka, who campaigned on his consistent votes against the Iraq war and his congressional seniority as reasons voters should back him.

While the Senate race attracted the most interest, voters also picked candidates for Hawaii's two congressional districts, governor, and state and local positions.

Democratic-leaning Hawaii has never unseated an incumbent member of Congress since it became a state in 1959, but Case has centered his campaign around the idea that voters need to boot Akaka in favor of a more youthful representative who can start to build up seniority.

Some voters leaving the polls Saturday who supported Akaka said they valued his seniority and consistent record.

``Experience does matter. I didn't like the dirty comparisons'' that Case made in TV ads, said Ted Awaya of Honolulu.

Others backing Case said they wanted a new face in the Senate.

``I think we need a change. We've been in a stalemate for too many years and we needed someone new,'' Nancy Clines said.

Two recent polls had showed Akaka with a substantial lead among likely Democratic voters, but many residents were undecided and Case could benefit from Republicans and independents who take a Democratic ballot in the open primary.

Hawaii has the lowest voter turnout in the nation, with even less participation in primaries. Only 40 percent of 626,000 registered voters cast ballots in the 2004 primary.

Akaka, who drew endorsements from leading Senate Democrats, held more than a 2-to-1 advantage in fundraising, collecting more than $2 million to Case's $817,000 by early this month.

The race for Case's congressional seat developed into a free-for-all, with a dozen experienced candidates seeking the nomination. The primary winner is favored to win the general election, keeping Hawaii's congressional delegation all Democratic.

Three little-known Democrats competed to take on Republican Gov. Linda Lingle in November. Lingle easily secured the GOP nomination on Saturday and will face former state Sen. Randy Iwase, who defeated Hawaiian activist William Aila by a wide margin.

Election officials used a new form of electronic voting that will leave a paper trail to help verify votes.