One of the arguments gay-rights advocates made in pushing to revive civil unions at the end of the 2010 Legislature was that they had a "hunch" Gov. Linda Lingle would let it become law even though it lacked a veto-proof majority in the House.

Lingle has always portrayed herself as a moderate Republican on social issues, and while she's opposed same-sex marriage, she said during the 2002 campaign that she wouldn't veto a domestic partnerships bill that gave gay couples "certain rights" of marriage.

Supporters of House Bill 444 now take hope from that and her promise to hear all sides before deciding by July 6 whether to sign the bill, veto it or let it become law without her signature.

They're probably right that deep in her heart the governor has no philosophical problem with civil unions. But from the standpoint of 2010 politics, it would be a surprise if Lingle allowed HB 444 to become law.

The immediate political consequence is that it would set her at odds with her lieutenant governor, James "Duke" Aiona, the leading opponent of the measure, and undercut one of his major issues in his already uphill campaign to succeed Lingle.

Aiona has been Lingle's loyal partner, and she wouldn't likely do that to him unless she had strong personal feelings on the issue that surely would have surfaced before now.

Lingle also will have an eye to her own political interests.

For much of her term, her moderate views and efforts to reach accommodation with the Democratic Legislature created such tensions with GOP conservatives that many referred to her as a RINO — Republican in Name Only.

As her time as governor nears an end and she eyes a future in a Republican Party that has turned sharply to the right since losing the presidency and Congress to Barack Obama and the Democrats, Lingle has worked hard to shore up her conservative flank.

She turned jeers from the right into cheers by hedging her support for O'ahu rail transit and the Akaka bill for Native Hawaiian political recognition. She's also won points in the party for stepping up her rhetoric against higher taxes and battling the public worker unions.

It's difficult to imagine her undoing all the gains she's made within the GOP by crossing the party on gay unions, one of the biggest conservative litmus tests.

If Lingle does veto HB 444, she probably won't do it with a lot of thundering about the sanctity of marriage.

More likely, she'd base it on technical grounds. The Demo- crats left her plenty of room to maneuver with their herky-jerky movement of the bill through two legislative sessions.

The most obvious target would be an inadvertent retroactivity clause that raises legal and financial concerns.

Of more import are the uncertain consequences of the Legislature's decision to extend the rights of civil unions to heterosexual couples as well as gays.

As first passed by the House, HB 444 applied only to homosexual partners, but Senate leaders amended the measure to include straight couples as a parliamentary dodge to prevent its passage at the end of the 2009 session.

That was the version passed by the Senate at the start of 2010 and the House at the end of the session, but in all that time, lawmakers did no detailed study of what it would cost government and private businesses to extend marital rights and employee benefits to unmarried heterosexual couples as well as gays.

It's an oversight that could give Lingle wiggle room to avert questions about her 2002 promise to gays by focusing a veto on the ramifications of extending the law to straights.