WASHINGTON - As the House of Representatives prepared to vote on a resolution condemning President Donald Trump’s incendiary tweets about four minority lawmakers, he lashed out at the freshman Democrats again on Tuesday and questioned why Congress was not rebuking them instead.

In a string of tweets throughout the morning, Trump also insisted his tweets were not racist — “I don’t have a Racist bone in my body!” he wrote — and urged fellow Republicans not to fall into a “trap” by voting Tuesday night on the Democratic-backed resolution.

"The Democrat Congresswomen have been spewing some of the most vile, hateful, and disgusting things ever said by a politician in the House or Senate, & yet they get a free pass and a big embrace from the Democrat Party," Trump wrote on Twitter, listing several grievances about the lawmakers. "Why isn't the House voting to rebuke the filthy and hate laced things they have said? Because they are the Radical Left, and the Democrats are afraid to take them on. Sad!"

His tweets marked the third day in a row of attacks on the lawmakers — a series that began Sunday with tweets in which the president said the four Democrats should “go back” to “the crime infested places from which they came.” Three of the lawmakers were born in the United States, and the fourth is a naturalized U.S. citizen who was born in Somalia.

Trump has not spelled out what specific comments from the congresswomen that he finds objectionable, and the White House has declined to provide more details.

Trump has been accused of racially inflammatory rhetoric both before and after assuming the presidency, including his questioning of former president Barack Obama's birthplace, his assessment that there were "very fine people" on both sides of a deadly confrontation in Charlottesville, Virginia, and his musing that a federal judge could be biased against him given his Mexican heritage.

The resolution scheduled for a vote Tuesday night “strongly condemns President Donald Trump’s racist comments that have legitimized and increased fear and hatred of new Americans and people of color.”

With his tweets Tuesday, Trump made clear that he doesn’t want Republicans to support the resolution. Doing so, he said, would “show ‘weakness.’”

At a news conference, House Minority Leader Kevin McCarthy, R-Calif., said he would vote against the resolution and encourage other Republicans to vote against it as well. McCarthy said he did not consider Trump’s tweets to be racist.

"I believe this is about ideology," he said. "It's about socialism versus freedom."

Congressional Republicans were largely silent Sunday after the Trump’s initial tweets — with some fearful of chastising a president popular with the party’s base — although a handful began speaking out critically Monday.

Tuesday's vote will be a rare occasion when members of a Republican caucus that is overwhelming white and male will be forced to go on the record regarding Trump's controversial rhetoric. During Trump's first two and a half years in office, many lawmakers in his party have gone to great lengths to avoid criticizing him.

Meanwhile, the rebuke of Trump presents an opportunity for the Democratic caucus to unite around a common aim at a time when there has been infighting between House Speaker Nancy Pelosi, D-Calif., and the four liberal lawmakers informally known as “the Squad” on Capitol Hill.

"We've got to say something," said Rep. Emanuel Cleaver II, D-Mo. "I think we would be complicit as a Congress if we didn't speak out on this. All of us, people of color in my generation, we've heard the 'go back to Africa' stuff since I was a little boy growing up down in Texas. So we have to say something."

The four Democrats — Reps. Alexandria Ocasio-Cortez of New York, Ilhan Omar of Minnesota, Ayanna Pressley of Massachusetts and Rashida Tlaib of Michigan — held a news conference Monday in which they described themselves as part of a nation of tolerance that offers opportunity to people like themselves. Pressley was born in Cincinnati, Tlaib was born in Detroit and Ocasio-Cortez was born in New York. Omar was born in Mogadishu, Somalia; her family fled the country amid civil war when she was a child, and she became a U.S. citizen as a teenager.

In a tweet on Tuesday, Ocasio-Cortez, who represents a district that includes part of Queens, took issue with Trump’s contention that he is not a racist.

“You’re right, Mr. President — you don’t have a racist bone in your body,” she wrote. “You have a racist mind in your head, and a racist heart in your chest. That’s why you violate the rights of children and tell the Congresswoman who represents your home borough, to ‘go back to my country.’”

Several Democratic lawmakers said Tuesday that while they supported the resolution backed by House leaders, they were interested in a more forceful response — such as a censure resolution introduced by Rep. Steve Cohen, D-Tenn., and supported by the four liberal freshmen.

“I think there’s going to be a number of responses, and frankly I think what the president did was so egregious I think all of the responses are good,” said Rep. Karen Bass, D-Calif., chair of the Congressional Black Caucus. “So we’ll see what happens.”

House Rule Committee Chairman Jim McGovern, D-Mass., a close Pelosi ally, said he was "not opposed" to censure but wanted to keep the focus of the day on the resolution so members can express their "deep reservations of concern on the House floor."

“Look, this is an important vote we’re going to have today. This is the first time that I can recall that we’re actually. . . condemning the president for his words, which were racist, and it’s disgusting,” he said. “This is not normal. This is so divisive.”

During a closed-door meeting of Democrats, Pelosi said she is hopeful the resolution condemning Trump’s tweet will win some Republican support.

"If they can't support condemning the words of the President, well that's a message in and of itself," Pelosi said, according to a Democratic official in the room, who spoke on the condition of anonymity to freely discuss internal discussions.

In his latest tweets, Trump accused the four lawmakers of being “Horrible anti-Israel, anti-USA, pro-terrorist” and took issue with the “public shouting of the F . . . word, among many other terrible things.”

All four lawmakers have called for Trump's impeachment, and Tlaib has done so using profane language.

Trump frequently used profanity at his campaign rallies, including one in Portsmouth, New Hampshire, in February 2016 when he said that companies that have relocated overseas for more favorable tax rates can "go f--- themselves."

Trump's comments on Israel and terrorism appeared to target Omar and Tlaib.

Earlier this year, Omar apologized after she was widely accused of anti-Semitism for suggesting that supporters of Israel's government have an "allegiance to a foreign country." She also came under scrutiny for a speech in which, while defending Muslims who lost their civil liberties in the wake of the Sept. 11, 2001, terrorist attacks, she said that "some people did something," referring to the hijackers.

Tlaib, the daughter of Palestinian immigrants, has advocated a "one-state solution" to the Israeli-Palestinian conflict. Arguing that the Israeli government of Prime Minister Benjamin Netanyahu effectively opposes the establishment of a Palestinian state alongside Israel, she has supported the transformation of Israel into a single, jointly governed Arab-Jewish nation. The idea has little support among either Israelis or Palestinians.

In a later tweet Tuesday morning, Trump wrote: "Our Country is Free, Beautiful and Very Successful. If you hate our Country, or if you are not happy here, you can leave!"

That echoed comments Trump made Monday at a White House event staged to promote American-made products. At the event, Trump alleged the four lawmakers "hate our country" and said they should leave if they are unhappy.

In other tweets Tuesday, Trump repeated his assertion that the four lawmakers "hate our Country."

"Nancy Pelosi tried to push them away, but now they are forever wedded to the Democrat Party," he added. "See you in 2020!"

The Washington Post’s Ashley Parker, Rachael Bade and Colby Itkowitz contributed to this report.