President Trump apparently better invest in a facemask soon because former Rep. Joe Walsh (R-Ill.) is officially challenging him in the Republican primary.

Walsh, who recently said somebody needs to punch Trump "in the face every single day," unveiled his campaign on Sunday during an appearance on ABC's This Week.

"We've got a guy in the White House who is unfit, completely unfit to be president, and it stuns me that nobody stepped up, nobody in the Republican Party stepped up," he told host George Stephanopoulos. "Because I'll tell you what, George, everybody believes in the Republican Party, everybody believes that he's unfit."

Walsh was also self-critical during the interview, acknowledging that he regrets helping "create" Trump. "The personal, ugly politics. I regret that," Walsh said. "And I'm sorry for that. And now we've got a guy in the White House, that's all he does." Walsh is reportedly going to attack Trump from the right on moral grounds.

He also announced the launch of his campaign on Twitter, joining former Massachusetts Gov. Bill Weld as Trump's GOP challengers. Tim O'Donnell

President Trump's "internal polling must be terrible, because he is now reaching out to people who want nothing to do with him — and this time, it's not Melania," Stephen Colbert said on Tuesday's Late Show. "Last night, the president held a rally in a state he lost last time by 8 points, New Mexico," and "after four years of Donald Trump throwing Latinos under the bus that he stopped at the border," his "plan to win is to woo Hispanic voters. Woo boy!"

"Buenos suerte with that, El Trumpo," Colbert said. "Trump must really need los hombres hispanico, because he laid it on muy thick," and un poco weird. When he singled out one Latino supporter, Steve Cortes, for example, he asked him a puzzling question. "Who do you like more, Steve, the country or the Hispanics?" Colbert repeated in Trump voice, adding, "Because I can't decide which to destroy first."

Trump clearly "tried to tailor his message to the crowd, and I'm not going to lie — it got a little bit uncomfortable," Trevor Noah said at The Daily Show, playing more of the clip. "What do you like more, the country or Hispanics? Those two things aren't even in the same category. 'What do you like better, Pepsi or Mongolia?' It's also a sh-tty question because it implies that Hispanics aren't a part of the country."

"When Trump wasn't busy torturing Hispanic people with weird mind games, he tried to stay focused on going after his Democratic rivals, but in the middle of his rant, a fly buzzed in front of Trump's face, and that totally threw the president off," Noah laughed. And while Trump was in New Mexico, "bragging about how he helped the mega-rich keep their cash," across the country, Democratic rival "Elizabeth Warren was talking about making the super-rich pay more, 2 cents more," at a dueling campaign rally in New York. And after her speech, he added, "Warren spent four hours taking selfies with her supporters — it took three hours to get through most of the crowd, and then an extra hour for that annoying person who's never satisfied."

The Late Show also created a whole backstory for that fly who blitzed Trump. Watch that below. Peter Weber

Wearing just a cap, goggles, and swimsuit, Sarah Thomas got into the water Saturday and emerged more than 54 hours later, a world record holder.

On Tuesday, the 37-year-old from Colorado became the first person to ever swim across the English Channel four times in a row, nonstop. It was a commendable feat, as only four other swimmers have crossed the English Channel three times without stopping. An open water ultra marathon swimmer, Thomas was hooked on the sport after entering her first race in 2007. She swam the English Channel in 2012 and 2016, but after completing breast cancer treatment last year, she wanted to take on this challenge, saying her swim was for "all the survivors out there."

Going into it, Thomas expected to swim about 80 miles, but strong tides tacked on 50 additional miles. The hardest parts included getting stung on the face by a jellyfish and having to deal with the saltwater burning her throat, mouth, and tongue, but Thomas pushed through, buoyed by her supporters and the protein drinks she downed every 30 minutes. Once she was back on land, Thomas told BBC News she was "stunned" and couldn't believe she did it. "I'm really just pretty numb," she added. Catherine Garcia

In response to drone attacks against Saudi Arabian oil facilities over the weekend, the Trump administration is contemplating several different ways to retaliate against Iran, U.S. officials told NBC News on Tuesday.

U.S. intelligence says there is strong evidence that Iran was behind the attack, an accusation Tehran denies. During a national security meeting on Monday, Trump was presented with several ways the U.S. could target Iran, including a strike against oil facilities or a cyber attack, NBC News reports. Trump wants to avoid being drawn into a larger military conflict with Iran, the officials said, and asked for more options.

On Monday, Trump said the U.S. is prepared for war, but "we'd certainly like to avoid it," and he thinks the Iranians "want to make a deal." Catherine Garcia

The Trump administration will formally revoke California's right to set its own stricter vehicle emissions rules this week, setting up a massive legal fight with high-stakes consequences for U.S. automakers and greenhouse gas emissions. The Environmental Protection Agency was scheduled to announce its unprecedented withdrawal of California's waiver on Wednesday, while Trump is raising more money in California, but after the news broke, the announcement has been pushed back to at least Thursday, The Washington Post reports.

The Trump administration has long signaled it will revoke California's special authority to set its own auto emissions standards, granted under the 1970 Clean Air Act. Other states gained the right to adhere to California's stricter standards under a 1977 law, and 13 states have pledged to follow California's current rules.

California vowed to fight the waiver withdrawal all the way to the Supreme Court, and environmental groups have signed on. Stripping California of the right to control its own air quality "could have devastating consequences for our kids' health and the air we breathe, if California were to roll over," Gov. Gavin Newsom (D) said. "But we will not." In a speech to the National Automobile Dealers Association on Tuesday, EPA Administrator Andrew Wheeler said "we embrace federalism and the role of the states, but federalism does not mean that one state can dictate standards for the nation."

Trump's move against California was originally supposed to be part of a broader rollback of fuel economy standards set under President Barack Obama, but the rest of the plan has gotten bogged down "as staff members struggled to prepare legal, technical, or scientific justifications for it," The New York Times reports. Wheeler told the Post last week that the rest of the rules will be finalized by the end of the year. But Trump "wanted to press forward with a policy that would punish California," the Times reports, after he was "blindsided and angered" by a deal California forged with four large automakers in July to adhere to California's goal of higher-efficiency vehicles by 2026 regardless of what the Trump EPA decides. The Justice Department is also examining whether that deal violates antitrust laws. Peter Weber

The results of Israel's Tuesday election are starting to trickle in, and the race is too close to call.

With 26 percent of votes counted early Wednesday, Prime Minister Benjamin Netanyahu's right-wing Likud party has 28.42 percent of the vote, followed by the centrist Blue and White Party with 25.4 percent. Exit polls showed that Netanyahu did not appear to have enough votes for a parliamentary majority, and the Central Elections Commission told the Times of Israel the final tally might not be known until Wednesday afternoon.

The commission also said 69.4 percent of eligible voters cast their ballots, with higher turnout among Arab voters; this was likely due to Netanyahu's actions before the election, when he questioned their loyalty and vowed to annex settlements in the West Bank.

Speaking to supporters late Tuesday, Benny Gantz of the Blue and White Party said that "starting tonight, we will work to form a broad unity government that will express the will of the people." At his rally, Netanyahu said the country "needs a strong and stable and Zionist government." He touted his relationship with his "close friend President Trump," and declared there can't be a government "that is being supported by anti-Zionist, Arabic parties that don't believe in Israel as a Jewish and democratic state."

Netanyahu is expected to be indicted soon on bribery, fraud, and breach of trust charges related to three separate scandals. He wanted to secure a majority so he could work with his allies to pass legislation giving him immunity, The Associated Press reports. Catherine Garcia

The United States wants Cuban migrants who pass through Honduras to seek asylum there, rather than in the U.S., Honduran Foreign Minister Lisandro Rosales said Tuesday.

Rosales told reporters that over the last year, thousands of Cubans have made their way through Honduras, headed to the United States. Negotiations are ongoing between the U.S. and Honduras on what to do about migrants, and "one of the topics discussed in the deal with the United States is precisely that if Cuban migrants are interested in seeking political asylum ... they do so in Honduras," Rosales said.

Looking for ways to stop the flow of migrants to the U.S., the Trump administration has worked out an agreement with Guatemala, so migrants headed toward the United States can first apply for asylum there. The Guatemalan government has not yet ratified this deal. Thousands of Hondurans and Guatemalans are leaving their countries every year for the United States, fleeing poverty and violence. Catherine Nichols