WASHINGTON - Republican presidential candidates on Wednesday slammed President Obama's policies toward Israel, accusing him of undermining security in the Middle East.

Addressing the Republican Jewish Coalition at a daylong forum, the candidates contended that Obama had coddled Iran, emboldened terrorist groups, and taken a more sympathetic approach toward Palestinians than Israelis.

"This one-sided, continuing pressure that says it's always the Israelis' fault no matter how bad the other side is has got to stop," said former House Speaker Newt Gingrich, one of six GOP contenders to address the coalition.

The Republican candidates have tried to make Israel an issue in the 2012 campaign as they jockey for support of Jewish voters who traditionally have voted overwhelmingly Democratic. In speech after speech, they lambasted Obama's foreign policy and questioned his support for Israel.

Gingrich called for the overthrow of Iranian President Mahmoud Ahmadinejad and Syrian President Bashar al-Assad. He vowed to move the U.S. Embassy in Israel from Tel Aviv to Jerusalem, a sensitive topic in peace talks between Israelis and Palestinians. And he promised, if elected, to appoint John Bolton, the former U.S. ambassador to the United Nations, as secretary of state, prompting wild applause from the standing-room-only audience.

Former Massachusetts Gov. Mitt Romney told the several hundred activists that Ahmadinejad should be "indicted for the crime of incitement to genocide."

"Ultimately, regime change is what's going to be necessary" in Iran, Romney said.

Romney and Gingrich have called on Obama to fire the U.S. ambassador to Belgium, Howard Gutman, who is Jewish and the son of Holocaust survivors, after the diplomat said recently that some anti-Semitism stemmed from tensions between Israelis and Palestinians.

Republican candidate Jon Huntsman, a former ambassador to China under Obama, said Gutman's comments reflected deeper anti-Israel attitudes within the Obama administration.

"These aren't speeches that are cooked up at the local level and at the embassy," he said. "They go high up within the State Department."

The White House and its Democratic allies moved quickly to counter the criticism. Rep. Nita Lowey (D., N.Y.) called the candidates' comments "highly irresponsible" and "shameful."

Bill Burton, a former Obama aide now leading independent fund-raising efforts for his reelection, accused Romney and Gingrich of continuing to "play politics with false attacks on the president."

Obama "has consistently fought for a secure Israel and peace in the Middle East," he said in a statement.

Democrats are also increasing their outreach to Jewish voters. Obama aides plan a Hanukkah party Thursday at the White House for Jewish leaders. Next week, Obama will address several thousand North American Jews at an annual conference of the Union of Reform Judaism.

Obama won election in 2008 with 78 percent support from Jewish voters, according to national exit polls. Republicans seek to win increased support from Jewish Democrats and independents to help their party carry swing states, including Florida.

At a Nov. 30 fund-raiser in New York, Obama called Israel one of the United States' most important allies.

"I try not to pat myself too much on the back, but this administration has done more in terms of the security of the state of Israel than any previous administration," Obama said at the event.

But former Pennsylvania Sen. Rick Santorum on Wednesday compared Obama's policies in the Mideast to actions taken by England before World War II to try to avert the conflict. "For every thug and hooligan, for every radical Islamist, he has had nothing but appeasement," Santorum said.

The coalition did not invite Texas Rep. Ron Paul to the forum, citing his "misguided and extreme views." Paul has argued that the United States should have less involvement in Israeli affairs and criticized foreign aid to the country.