Updated Aug 21., 1:52PM

WASHINGTON - Republican U.S. President Donald Trump has sparked a new political fight with American Jews by suggesting they show "great disloyalty" by voting for opposition Democrats.

U.S. Jews for decades have overwhelmingly voted for Democratic presidential candidates over their Republican challengers, including Trump, even as he won the presidency in 2016.

But Trump on Tuesday attacked Jewish people who vote for Democrats, saying they are showing "either a total lack of knowledge or great disloyalty."

On Wednesday, he clarified what he meant, saying votes for Democratic candidates are "disloyal to Jewish people and to Israel."

Trump's Tuesday attack came as he again assailed two first-term Muslim lawmakers, Congresswomen Ilhan Omar and Rashida Tlaib, both vocal critics of Israel and its treatment of Palestinians, who were denied entry to Israel last week after Trump pressured the Israeli government to keep them out. Tlaib was later granted permission to visit on humanitarian grounds but she said he wouldn't go, citing what he called Israeli's "oppressive" conditions on her visit.

"Where has the Democratic Party gone?" President Trump said. "Where have they gone where they're defending these two people over the state of Israel?"

Democratic presidential candidates seeking their party's nomination to run against Trump in the 2020 election and Jewish leaders were quick to condemn his remarks.

"My message to Trump: I am a proud Jewish person and I have no concerns about voting Democratic," said Senator Bernie Sanders, one of the leading Democratic candidates.

The top polling Democrat, former Vice President Joe Biden, said Trump's comments were "insulting and inexcusable." Former Texas Congressman Beto O'Rourke said, "The Jewish people don't need to prove their loyalty to you, @realDonaldTrump - or to anyone else."

J Street, a liberal, Washington-based lobbying group, was among several Jewish groups that assailed Trump's remarks.

"It is dangerous and shameful for President Trump to attack the large majority of the American Jewish community as unintelligent and 'disloyal,'" J Street said.

The American Jewish Committee called Trump's comments "shockingly divisive."

"American Jews -- like all Americans -- have a range of political views and policy priorities," said committee chief executive David Harris. "His assessment of their knowledge or 'loyalty,' based on their party preference, is inappropriate, unwelcome, and downright dangerous."

Later, on Twitter, Trump praised conservative writer Wayne Allyn Root, who called the U.S. leader "the greatest President for Jews and for Israel in the history of the world."

Root said, "The Jewish people in Israel love him like he's the King of Israel. They love him like he is the second coming of God. But American Jews don't know him or like him."