What will Chuck Schumer do if he has to choose between the Democrats and Israel? The question begs for an answer with the rise of the party’s new “it” politician, Alexandria Ocasio-Cortez.

She’s the Democratic Socialist who toppled Joe Crowley in the Democratic primary in New York’s 14th Congressional District. She’s a nightmare for the Jewish state.

No one’s arguing Israel is the only, or even primary, issue before Congress. Nor is Schumer the only Democrat of the ilk whose more centrist policies are being challenged by Ocasio-Cortez.

Schumer, though, has spent a career presenting himself as Israel’s greatest defender. How’s Schumer going to protect that brand if Ocasio-Cortez wins in November?

Even the liberal Israeli daily Haaretz reports that Ocasio-Cortez “is seen as the embodiment of the Democrats shifting away from Israel.” It’s not hard to see why.

Ocasio-Cortez’s progression on the issue of Israel is shocking. She jumped right in, bashing Israel’s handling of the attacks from Gaza, characterizing Israel’s defense as a massacre.

On Friday, Ocasio-Cortez was asked about that on “Firing Line” with Margaret Hoover. The young socialist claimed she supports a two-state solution, then went on about “the occupation of Palestine.”

Ocasio-Cortez talked of “an increasing crisis of humanitarian condition,” adding that is “just where I tend to come from on this issue.” Hoover asked what she meant by the occupation of Palestine.

“Oh, um,” Ocasio-Cortez stumbled. She then complained about the settlements, before confessing she is “not the expert on geopolitics on this issue.”

Two days later, Amy Goodman of “Democracy Now” asked Ocasio-Cortez whether she “still” believed in a two-state solution. The Bronx socialist backpedaled, saying she’s consulting with “activists.”

Good luck with that. No one expects the 28-year-old Ocasio-Cortez to have all the answers at the start of her political career. Guess, though, how the activists will steer her.

The test to watch is that of the pro-Israel Democrats. One of the greatest, former Connecticut Sen. Joe Lieberman, is out with a piece in The Wall Street Journal arguing that Ocasio-Cortez’s foreign policy is straight from the Democratic Socialists of America “policy book.” That means, he reckons, support for even corrupt, socialist regimes. Like Venezuela’s.

It also means, he writes, opposition to American leadership even in humanitarian disasters like Syria. And “reflexive criticism” of one of America’s “great democratic allies” — Israel.

Lieberman wants Crowley to dodge his defeat in the Democratic primary by staying in the race on the Working Families’ line rather than bow to pressure to unite the Democrats behind Ocasio-Cortez by finding an easy way off the third-party ballot. Crowley insists he’s behind Ocasio-Cortez, but Lieberman wants him to actively campaign for his seat.

Lieberman speaks from experience. In 2006, as Lieberman sought a fourth term in the Senate, a left-wing candidate won the Democratic primary. Lieberman promptly turned around and ran as an independent. He won handily by winning a majority of the Republican votes and a third of the Democrat ballots.

Could Crowley pull off such a triumph? It’s hard to imagine, unless he gets help.

So why isn’t the pro-Israel leadership in the Democratic Party scrambling to keep Crowley in Congress? He could caucus with the Democrats, as Lieberman did.

Which gets back to the question of Schumer. All sorts of Democrats are sounding the alarm. They seem to get what Ocasio-Cortez’s pseudo-Marxist agenda represents for the party.

They range from the former speaker, Nancy Pelosi, to Congressmen Alcee Hastings of Florida (“meteors fizz out”) to Bill Pascrell of New Jersey (“she ain’t gonna make friends”), to name a few.

Few Democrats are marking Ocasio-Cortez’s denigration of Israel. So far it looks like Schumer is taking a powder, just as he did on the Obama administration’s appeasement of Iran.

It may not be so easy to hide from the movement of which Ocasio-Cortez is a part. Another major centrist Democrat, Dianne Feinstein, is fighting for her political life against a California radical.

Israel might not figure in the California race. In New York, it’s another story. If a high-profile Democratic critic of Israel accedes to the House from New York, how will it look if Schumer failed to speak up?