With less than four months to go before the start of the Democratic primaries, two Democratic candidates for president have indicated that they would consider using aid to Israel as leverage in working towards a two-state solution and preventing Israel from annexing the West Bank.

At an event at the University of Chicago last Friday, South Bend, Ind. Mayor Pete Buttigieg said he viewed leveraging aid to Israel as a way to “guide Israel in the right direction.”

“If, for example, there is follow-through on these threats of annexation, I’m committed to ensuring that the U.S. is not footing the bill for that,” said Buttigieg.

At an event in Iowa on Saturday, Sen. Elizabeth Warren said “everything is on the table” when it comes to preventing Israel from annexing settlements in the West Bank.

“Right now, [Prime Minister Benjamin] Netanyahu says he is going to take Israel in a direction of increasing settlements — that does not move us in the direction of a two-state solution,” she said.

The comments from Warren and Buttigieg are the latest example of the leftward swing of the Democratic Party as the candidates on the progressive flank, led by Warren and Bernie Sanders, go head to head with the moderates, led by Joe Biden. Sanders has held a similar position to Warren and Buttigieg’s for months, saying in the summer that he would use aid to Israel to pressure Israel’s government to act differently.

Taken together, the comments show an increasing willingness among some Democrats to put to use the once-verboten tactic of withholding military aid to pressure on Israel, which in recent years has moved closer to official annexation of the West Bank.

The comments from Warren and Buttigieg are made more significant by their status in the polls. According to a recent Suffolk University/USA TODAY poll of likely Democratic caucus goers in Iowa, where the caucuses are on Feb. 3, Warren and Buttigieg are ranked second and third, with 17 percent and 13 percent respectively, coming close behind former Vice President Joe Biden at18 percent. Sanders, who suffered from a heart attack earlier this month and recently held a rally here with over 25,000 people, where he was endorsed by progressive Queens-Bronx Rep. Alexandria Ocasio-Cortez, came in fourth at 9 percent. The poll was conducted Oct. 16-18 with 500 likely Democratic caucus goers and has a margin of error of 4.4 points.

National polls have been less rosy for Buttigieg. A Morning Consult poll of 11,521 Democratic primary voters from Oct. 16-20 showed Joe Biden with 30 percent of respondents’ support, Warren at 21 percent, and Sanders at 18 percent. A CNN/SSRS poll conducted from Oct. 17-20, among a sample of 1,003 respondents, showed Biden at 34 percent, Warren at 19 percent, and Sanders at 16 percent. Buttigieg received 6 percent of respondents’ support in both polls.

IfNotNow, the anti-occupation organization that has been asking candidates on the trail about what they will do to end Israel’s occupation of the West Bank and to stop annexation, called Buttigieg and Warren’s answers “encouraging.” An IfNotNow member had asked the question to Buttigieg in Chicago.

Mark Mellman, president and CEO of Democratic Majority For Israel, a group formed earlier this year to shore up Democratic support for Israel, suggested that leveraging U.S. military aid to Israel would be a departure from past Democratic policy.

“President Obama promised U.S. military aid to Israel for 10 years in writing. Presidents Obama and Clinton both understood that aid was vital for the U.S. and Israel, and never publicly threatened to cut it,” said Mellman in a statement. “Both also got Israel to freeze settlement construction without such public threats.”