Winning 62 percent of the vote usually counts as a landslide — but not for a two-term incumbent running with strong party backing against an unknown challenger who spent no money and didn’t even campaign.

Which is why New Jersey Republicans now think they have a chance to capture scandal-scarred Democrat Bob Menendez’s Senate seat.

Nearly four in 10 Democrats voted in Tuesday’s primary for Lisa McCormick, a virtually unknown newspaper publisher, to send a pointed message: Menendez may be off the legal hook, but all is not forgiven.

His recent trial on corruption charges ended in a hung jury, and prosecutors opted not to re-try him. But the Senate Ethics Committee admonished Menendez for breaking the law by accepting lavish gifts from a longtime donor.

The GOP nominee, drug-company ex-CEO Bob Hugin, is running as a very un-Trumpian centrist — pro-choice, pro equal-pay-for-equal-work and promising to cooperate with Democrats. He also says he’ll spend a good part of his personal wealth on the race, with a heavy ad blitz.

He’s still a long shot: Republicans haven’t won a US Senate race in Jersey since 1972.

But Menendez’s weak showing means he’s got a fight on his hands — as he should. Voters clearly remain wary of his ethics (or lack thereof), and may well respond to a credible, well-financed opponent who vows to give New Jersey “a senator we can be proud of.”

The Garden State clearly deserves that — and Bob Menendez clearly deserves to lose.