WASHINGTON — Israeli Prime Minister Benjamin Netanyahu has made little secret of his fondness for President Trump: He’s a guy who plastered a 65-foot billboard of himself shaking hands with Trump in downtown Tel Aviv.

But this week, even some of Israel’s staunchest supporters warned he took it too far, and risks alienating a key group Israel has relied on for decades: Democrats.

Netanyahu’s decision to block two Democratic Congresswomen, Rep. Rashida Tlaib and Rep. Ilhan Omar, from visiting his country revealed a willingness to throw down against Trump’s domestic political opponents.

But his bromance with Trump could backfire once a Democrat eventually returns to the White House, diplomats and national security experts told VICE News. If Democrats come to see support for Israel as a GOP issue, they might back away from policies Israel has relied on for decades to ensure its security, including billions in foreign aid and full-throated diplomatic backing in the United Nations.

“Israel has become weaponized in Trump’s bid for reelection,” said Martin Indyk, who was U.S. ambassador to Israel under former President Bill Clinton. “It doesn’t make any sense for leadership in Israel to allow support for Israel to be turned into a partisan cause. But that’s exactly what Netanyahu, and Trump, are doing.”

Decades of support from both parties has resulted in $142 billion in foreign aid since World War II, more than any other country. But Democrats declared themselves outraged by a decision that House Speaker Nancy Pelosi criticized as “beneath the dignity of the great State of Israel.”

“My fear is that this move to bar two Congresswomen is turning Israel into a political football in the United States, and will give ammunition to those who want to see the relationship fall apart,” said Yaakov Katz, Editor-in-Chief of The Jerusalem Post.

Trump, Democrats and Israel

A Democrat who replaced Trump would have plenty of options to change the status quo, to Israel’s detriment.

Pending approval from Congress on spending matters, the next president could:

Trim some of Israel’s annual $3 billion in aid

Limit arms sales

Reduce intelligence sharing

Withdraw diplomatic support for Israel in the UN

Signal to other middle eastern countries that American support has softened

“I think Israel could pay a price for Netanyahu’s kowtowing to Trump’s desires,” said Bob Dietz, who held senior roles in both the CIA and National Security Agency under former President George W. Bush. “I’m surprised Israel is going along with it.”

Some Democrats are already openly talking about going there. On Thursday night, Democratic Senator and presidential Candidate Bernie Sanders suggested cutting aid to Israel in response to the travel dispute.

“What is taking place is totally outrageous,” Sanders said on CNN. “You have two members of the United States Congress who were denied access to a country, Israel, which we spend many billions of dollars supporting. And if Mr. Netanyahu and others in Israel don’t want members of [the] U.S. Congress to visit them, maybe they don’t want U.S. money as well.”

Israel partly walked its decision back in the face of widespread blowback, saying it would allow Rep. Tlaib to visit her family in the West Bank. But Tlaib turned down the offer, saying she’d decided not to go, after all.

Netanyahu’s motives

Netanyahu’s unprecedented foray into U.S. domestic politics comes as he is fighting for reelection in a vote scheduled for next month.

His decision may be partly about angling for a political gesture from Trump, who remains popular in Israel, to help put him over the top in September’s vote, close observers of Israeli politics said.

It wouldn’t be the first time. In March, two weeks before Netanyahu’s last election, the U.S. recognized the Golan Heights as part of Israel, in what was widely seen as an attempt by Trump to give Netanyahu a political bounce before the vote.

Trump and Netanyahu appear to be tying their domestic political fates together.

“Netanyahu decided to promote his relationship with Trump as a way of gaining support,” said Indyk, who’s now a distinguished fellow at the Council on Foreign Relations. “He’s for sure going to be looking for Trump to do some more things for him.”