(CNN) - As the special election to replace former Rep. Anthony Weiner heats up in Brooklyn and Queens, the Republican candidate, Bob Turner, received a ringing endorsement Monday from one of the Empire State's top Democrats.
Former New York City Mayor Ed Koch announced his support Monday for Turner amid his hopes that the special election in the 9th congressional district, a strongly Jewish area, will become a referendum on President Barack Obama's policies on Israel.
In his anger over the president's May Mideast speech, which recommended that a peace solution include a return to Israel's pre-1967 borders with land swaps, Koch said in a statement Monday that Obama is "willing to throw [Israel] under the bus" and end relations with the state.
"The election of Bob Turner in a normally safe Democratic district running against President Obama's position on Israel...would send a message to his own party leadership as well as to President Obama," Koch said in a statement Monday.
The former mayor has repeatedly referenced the 2010 election of Sen. Scott Brown in Massachusetts, where a Republican captured a long held Democratic seat, as a move that got Obama's attention. And he hopes to see the same effect happen in NY-9 come Election Day on Sept. 13.
"Many in politics think my endorsement of Bob Turner is a quixotic effort – tilting at windmills" Koch said. "I do not."
Koch has been known in the past to cross party lines and endorse Republicans. In 2004, he backed President George W. Bush's re-election bid. He also supported Rudy Giuliani in the Republican's first run for New York mayor.
Koch hinted earlier in July he might endorse Turner, but only if the Republican went against his own party and pledged to avoid cuts in Medicare, Medicaid and Social Security.
The idea seemed unlikely, as Turner, who ran as a tea party-backed candidate against Weiner in 2010, is known as a favorite among fiscal conservatives.
But Turner surprised many last week when he said he would oppose Rep. Paul Ryan's budget plan, which would include spending cuts and privatization of certain entitlement programs.
Turner's opposition to the Ryan plan then gave Koch the go-ahead to endorse the Republican.
While the campaign acknowledged Turner had made the decision to oppose the Ryan budget plan, a promised statement articulating why has not been provided following several days of requests.
Registered Democrats outnumber Republicans by three to one in the district, and political analysts say Turner will have to show some resistance to his own party in order to appeal to independents.
"I think to win that district, he's got to oppose the Ryan plan because that district is not an arch-conservative, tea party voting district," said Doug Muzzio, a public affairs professor at Baruch College-CUNY. "If he placed a hard line tea party agenda, he ain't going to win."
While the Democrats have nominated an orthodox Jew, David Weprin, as their candidate, Koch said another Democratic win in the traditionally blue seat would fail to get the point across to Obama.
"David Weprin could not be an effective messenger," Koch said. "His election would be viewed by President Obama as simply that of another Democrat elected to office in what is one of the largest Jewish constituencies in the nation…"
In a statement, Weprin's campaign manager, Jake Dilemani, called Turner an "extremist Republican" and pointed to a June 8 National Review op-ed where Turner said he would have worked to cut the federal budget by 30 to 35 percent if he won the seat in 2010.
"Voters won't endorse that," Dilemani said.
But as the election nears, Turner said he'll need support from Democrats like Koch.
"I cannot win this race without the added support of Democrats and independents, so the Mayor's recognition of my independence and support for Israel is particularly meaningful to my campaign, both practically and symbolically," Turner said in a statement Monday.