Hawai'i's iconic senior U.S. Sen. Daniel Inouye won't likely draw much opposition when he runs for re-election next year at 86.

As chairman of the Senate Appropriations Committee and the self-proclaimed "king of earmarks" in Washington, the federal dollars he directs our way have become such a major leg of the local economy that many here shudder at the thought of his retirement.

Gov. Linda Lingle is the only Republican who could have credibly challenged him, but it would have been a long shot and there's no sign she gave it a serious thought.

Nonetheless, the 2010 election will be a revealing test of the strength of Inouye's coattails in other Hawai'i races.

Honolulu Mayor Mufi Hannemann is claiming Inouye's support over U.S. Rep. Neil Abercrombie in their likely Democratic primary showdown for governor, and Inouye is showing clear preference for state Sen. Colleen Hanabusa over former U.S. Rep. Ed Case in the race to succeed Abercrombie in the 1st Congressional District.

In recent years, however, there have been persistent questions about how much clout Inouye really has in Hawai'i Democratic Party politics beyond his own campaigns.

Last year, he was the leading Hawai'i backer of Hillary Clinton's campaign for president — going so far as to question the "localness" of the Hawai'i-born Barack Obama — but Obama nevertheless swamped Clinton 3 to 1 in Hawai'i's Democratic presidential caucuses.

Not only did rank-and-file Democratic voters ignore Inouye's lead, but the party hierarchy showed him little deference in allocating delegate slots to the Democratic National Convention.

The outcome was similar a couple of years earlier when the senator tried to mediate a dispute between competing Democratic factions in the state House of Representatives.

The majority group shrugged off Inouye's advice and then punished former Rep. Dwight Takamine for acting as Inouye's point person by dumping him as Finance Committee chairman.

Enmity from the 2008 presidential campaign appears to be spilling over into the governor's race.

Inouye and Abercrombie were once tight enough that they all but ran as a team the last time Inouye stood for re-election in 2004, with joint TV commercials in which they did a Master-and-Grasshopper routine.

But apparently, permanent hard feelings occurred after they butted heads in the presidential campaign when Abercrombie was an aggressive leader in the local campaign for Obama, a longtime family friend.

Many Democrats were surprised when Inouye showed up at Hannemann's mayoral headquarters on election night and wondered into the TV cameras whether his next stop would be Washington Place or Washington, D.C.

While Hannemann has actively courted Obama's favor since the election, during the campaign he stayed neutral in the presidential race until it was pretty much decided.

Inouye says he hasn't made an endorsement for governor, but doesn't dispute Hannemann's claim that the senator encouraged him to run. The mayor has conducted his exploratory campaign as though he and Inouye were joined at the hip.

The prospect of running without Inouye's blessing has hardly scared off Abercrombie; to the contrary, he's doubled down by announcing he'll resign from Congress early to campaign for governor full-time.

In the 1st Congressional District, Inouye was reportedly prominent among Democrats who urged Hanabusa to run as the "establishment" candidate to stop the independent Case, who got on Inouye's bad side when he unsuccessfully challenged U.S. Sen. Daniel Akaka in the 2006 Democratic primary.

There's also spillover from the presidential race here; Hanabusa chaired the Hawai'i Clinton campaign and stuck with Inouye to the end.

Inouye's support will no doubt help Hanabusa raise funds, but it remains to be seen how many votes he can deliver for her in a district where Case is well known and she's not.