Be afraid; be very afraid: That’s the message Hillary Clinton’s campaign is sending to supporters publicly after a new Quinnipiac poll showed her losing to Donald Trump in Ohio.

According to Quinnipiac, Trump has a four-percentage-point lead over Clinton in battleground Ohio. And Clinton barely edges him out in Florida and Pennsylvania, two other states that are likely to draw fierce competition in the general election.

Here are the numbers:

Florida: Clinton 43, Trump 42
Ohio: Clinton 39, Trump 43
Pennsylvania: Clinton 43, Trump 42

Clinton’s campaign manager, Robby Mook, told supporters in a fundraising email this morning that public polls are notoriously bad. But this one? “I need you to see it.”

“I can't say this enough times: These polls don’t predict the future,” Mook said. “We can change them by making sure voters know about Hillary’s vision for our country. But we need to get started RIGHT NOW.”

Got it?

It’s a convenient tactic by campaigns, especially this one: The best way to jump-start fundraising is to make your supporters worry. Complacency is the enemy of every political campaign, especially that of Clinton, who has been dogged by the perception of “inevitability” from the beginning.

As The Post’s Philip Bump notes, the Quinnipiac poll makes a few assumptions — most critically about the size of the white electorate — that contributed to the poll being more favorable to Trump. Only time — and an election — will tell whether this turns out to be true, but for now, the results are largely out of step with other polls, including a March NBC News/Wall Street Journal/Marist poll that showed Clinton with a six-percentage-point lead in Ohio. An April survey of Pennsylvania by the same poll gave Clinton a 15-point lead over Trump. And in March, an eight-point lead over Trump in Florida.

So is the Clinton campaign terrified? Unlikely. Campaign aides privately say that Quinnipiac’s assumptions are out of step with reality. But as a fundraising tool, the poll is pure gold.