Republicans have been overwhelmingly silent amid widespread backlash to racist tweets from President Donald Trump.

Trump on Sunday suggested "Progressive" Democratic lawmakers should "g o back and help fix the totally broken and crime infested places from which they came."

The tweets were seemingly aimed at four freshman Democrats and women of color, Reps. Alexandria Ocasio-Cortez of New York, Rashida Tlaib of Michigan, Ayanna Pressley of Massachusetts and Ilhan Omar of Minnesota.

Republican leaders have remained silent as Democrats and world leaders rebuke Trump's racist comments, which played into the "go back to Africa" trope.

Trump has extraordinarily strong support among GOP voters, and Republican lawmakers are afraid of alienating their constituents who are loyal to the president by criticizing him.

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In the 24 hours since President Donald Trump sent out blatantly racist tweets about Democratic lawmakers — playing off of the "go back to Africa" trope — the Republican party has responded with overwhelming silence.

The Republican party, which was founded on ideals of limited government and respect for the rights of individuals, has stood by while the president called on these lawmakers, who are all US citizens, to return to "broken and crime infested places from which they came." Republican leaders appear to be more afraid of alienating GOP voters loyal to Trump ahead of an election year than they are with upholding their party's purported values.

Trump directed his tweets at "'Progressive' Democrat Congresswomen" whom he said "came from countries whose governments are a complete and total catastrophe, the worst, most corrupt and inept anywhere in the world (if they even have a functioning government at all)."

"Why don't they go back and help fix the totally broken and crime infested places from which they came," Trump went on to say about these US citizens who've been elected to national office.

The president didn't mention any lawmakers by name, but his tweets were likely directed at Reps. Alexandria Ocasio-Cortez of New York, Rashida Tlaib of Michigan, Ayanna Pressley of Massachusetts and Ilhan Omar of Minnesota.

Read more: AOC fact-checked Trump's tweet seemingly telling her to 'go back' to 'broken and crime infested' country: I 'come from' the US

The four freshman Democrats have been unabashed critics of the president. They've also repeatedly made headlines in recent weeks amid Democratic party infighting, centered around disagreements with House Speaker Nancy Pelosi.

Since the tweets went out on Sunday morning, Trump has been fiercely decried by Democrats and world leaders. But the GOP has barely flinched.

Senate Majority Leader Mitch McConnell and House Minority Leader Kevin McCarthy have not addressed it and their offices did not immediately respond to requests for comment from INSIDER.

Top Republicans who once criticized Trump are now rushing to his defense

There was a time when top Republicans like Sen. Lindsey Graham appeared to be abhorred by Trump's rhetoric and propensity for attacking marginalized groups.

When Graham was running against Trump for the GOP presidential nomination in December 2015, for example, he decried him as a "a race baiting, xenophobic, religious bigot."

Fast-forward to 2019 and Graham is defending the president for racist tweets and condemning those the president attacked as a "bunch of communists" who are "anti-American."

Only a small number of congressional Republicans have gone against the grain and criticized Trump for his tweets.

Rep. Chip Roy of Texas said in a tweet that the president was "wrong to say any American citizen, whether in Congress or not, has any 'home' besides the U.S."

But Roy couched his denunciation with an endorsement of the president's immigration policies as he called on voters to ensure lawmakers who "refuse to defend America... be sent home 11/2020."

Rep. Will Hurd of Texas, who has often gone against Trump on immigration issues, also spoke out against the president's tweets and was more direct.

"Those tweets are racist, and xenophobic... It's also behavior that's unbecoming of the leader of the free world. He should be talking about things that unite, not divide us," Hurd said.

Other conservatives who have forcefully gone after Trump over his racist tweets have either recently left the GOP, like Rep. Justin Amash of Michigan, or don't currently hold public office, such as former Sen. Jeff Flake of Arizona.

Trump's popularity with GOP voters explains why Republican lawmakers have embraced him

Challenging Trump has proven to be a career killer for Republicans.

Take former Rep. Mark Sanford, for example, who was critical of the presidency and lost his primary in South Carolina last year after Trump attacked him on Twitter. Sanford, a former South Carolina governor, attributed his loss to crossing the president.

"It may have cost me an election in this case, but I stand by every one of those decisions to disagree with the president," Sanford said during his concession speech in June 2018.

Read more: Pence's chief of staff defends Trump's racist tweets, becoming the first White House official to comment on them

Katie Arrington, the state legislator who defeated Sanford, in her victory speech said, "We are the party of President Donald J. Trump."

Trump has displayed a remarkable resiliency with GOP voters through a host of scandals, including being accused of sexual misconduct by two dozen women, his former personal lawyer implicating him in campaign finance violations via a hush money payment to adult film star Stormy Daniels, downplaying deadly neo-Nazi violence in Charlottesville and an outcry over his administration's policy of separating migrant children from their parents at the border.

Polling has shown that even when voters feel Trump's behavior has been unbefitting of the office he serves in, they often still approve of him.

A recent Washington Post/ABC News poll found that one in eight voters believe Trump has behaved in an unpresidential way but still approve of his presidency regardless. And roughly two-thirds of this group said they'd vote for Trump over former Vice President Joe Biden — the current frontrunner for the 2020 Democratic presidential nomination.

Gallup puts Trump's approval rating at 41% overall, but it rests at a resounding 89% among Republican voters.

Indeed, the GOP is now firmly Trump's party, which boosts his chances of being reelected next year. Aware of this, Republicans in Congress hope to ride Trump's coattails, with many hailing his acheivements to win points with his millions of supporters and keep the campaign money flowing.

As the GOP tries to retake the House and defend their closely held control of the Senate, Republican lawmakers appear to be focusing on shoring up every vote they can with their constituents rather than taking a stand against racist statements from a president many of them laughed off as joke when he hopped in the 2016 presidential race just four years ago.