I had a conversation with U.S. Sen. Brian Schatz when U.S. Rep. Colleen Hanabusa was still deciding whether to run against him or Gov. Neil Abercrombie.

Schatz, who Abercrombie appointed to replace the late Sen. Daniel Inouye, guessed Hanabusa would run against him to try to fulfill Inouye’s wish that she succeed him.

I said, "You don’t get a U.S. Senate seat, possibly for life, without facing at least one stern test at the polls."

Schatz said, "I know."

His 1,782-vote victory over Hanabusa in the Democratic primary was as stern a test as he could have imagined, and it may not be his final exam.

Schatz is heavily favored against Republican Cam Cavasso in the general election for the final two years of Inouye’s term, but he’d have to run again in 2016 for a full six-year term.

His slim victory over Hanabusa leaves him vulnerable to another primary challenge in two years.

Hanabusa, who has yet to congratulate Schatz on his win or offer support in the general election, could well segue straight into a rematch.

Also potentially looking for a chance to move up is the ambitious U.S. Rep. Tulsi Gabbard.

But two years is a long time in politics, and time favors a smart incumbent.

Schatz would gain two more years of seniority, making it an even more compelling argument for a job where Inouye said seniority is everything.

He’d have two more years to build his already impressive fundraising network and close ties to prominent national Democrats.

He’d get two more years of distance from the unpopular Abercrombie.

Most importantly, he’d have two years to become better known to Hanabusa’s base among traditional local Democrats and show them he’s solidly mainstream and no threat to their values.

But Schatz would make a mistake to look past Cavasso, even though he got only 20 percent of the vote in his last run for the Senate against Inouye in 2010.

While nobody expects Schatz to match Inouye’s victory margin, it’ll be interpreted as weakness if Cavasso beats by much the 37 percent of the vote Linda Lingle got against Sen. Mazie Hirono in 2012.

Hanabusa needs some attitude adjustment if she hopes to remain a viable candidate.

She acted at times like the election was a probate case in which she was cheated out of her rightful inheritance, and the perception of entitlement cost her votes.

Her pique in defeat continues the theme and doesn’t play with many Democrats who expect more grace from candidates.

Gabbard must weigh the risk of gambling her House seat to challenge an incumbent senator.

She’s popular in the polls, but so was Ed Case in 2006, when he left a safe House seat to lose badly to former Sen. Daniel Akaka.

Reach David Shapiro at volcanicash@gmail.com or blog.volcanicash.net.