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

The Lincoln Project isn't going anywhere.

The PAC of President Trump-opposing Republicans and other moderates has built a social media behemoth based largely on trolling the president with pointed ads. And once it potentially achieves its goal of getting Joe Biden and other Democrats elected, it's looking to capitalize on that and build a whole media empire, Axios reports.

The Lincoln Project's Twitter account boasts a following that even exceeds the Republican party's, and has raked in millions of dollars from its supporters who'd like to see Trump out of the White House. To Ra Kumar, the project's representative at United Talent Agency, it's clear that "they know how to get audiences," he tells Axios.

So in the coming weeks, the Lincoln Project is expected to move beyond podcasts and TV ads and into Hollywood. For starters, the group is working with a documentarian to produce a non-fiction film after the election, Axios reports. Some TV networks are interested in running the project's livestreamed shows, a source says. TV studios are also reportedly reaching out to work with the Lincoln Project "to help develop a House of Cards-like fiction series," Axios reports — a comparison that probably doesn't help the project with allegations of stealing ideas and memes. Kathryn Krawczyk

Flu shots are already considered an important factor in combating the coronavirus pandemic, since widespread inoculations will hopefully help prevent medical facilities from becoming overwhelmed by dual diseases. But new research suggests flu shots may also play some role in preventing COVID-19 infections in the first place, The Scientific American reports.

A study, which has not yet been peer-reviewed, found that workers at Radboud University Medical Center in the Netherlands who received a flu shot during the 2019-20 season were 39 percent less likely than their colleagues to test positive for the coronavirus as of June 1, 2020. Non-vaccinated employees contracted the virus at a 2.23 percent rate, compared to only 1.33 percent of those who were vaccinated.

The preliminary research would certainly require further clinical trials — though the author of the study noted it would be unethical to compel a control group of subjects to be denied a flu shot — and there could be several reasons why the vaccinated group staved off infection more easily, including the possibility that they are generally more health conscious and took more COVID-19 precautions.

Still, there have been other studies that hint at a possible link between flu shots (and other vaccines, for that matter) and lower COVID-19 risk. Additionally, the Radboud research team conducted a laboratory experiment in which they took blood cells from healthy individuals, purified them, and exposed some of them to a flu vaccine. After allowing the cells to grow for a few days, the researchers exposed them to the coronavirus. A day later they found that the vaccinated cells produced more of several kinds of immune molecules that fight off pathogens than those that were initially left alone. Read more at The Scientific American. Tim O'Donnell

Former New York City Mayor Michael Bloomberg is reportedly funding last-minute ad campaigns in two states where Democrats see "opportunities to expand the map," including Texas.

Through his Super PAC, Bloomberg is funding television ad campaigns in Texas and Ohio expected to cost about $15 million, The New York Times reports. Aide Howard Wolfson explained to the Times that the former mayor conducted polling to find President Trump's potential vulnerabilities and decided on Texas and Ohio for this last-minute push. Bloomberg has already said he will spend $100 million to support Democratic presidential nominee Joe Biden in Florida.

"We believe that Florida will go down to the wire, and we were looking for additional opportunities to expand the map,” Wolfson told the Times. "Texas and Ohio present the best opportunities to do that, in our view."

The Times notes that a poll it published this week showed Trump with a lead of only four percentage points over Biden in Texas, and Wolfson told the Times that Bloomberg's polling suggests the race is even closer.

Meanwhile, NBC News on Tuesday morning released its latest battleground map, and Texas has been moved from "Lean Republican" to "Toss Up." Ohio is also still in the "Toss Up" category.

The NBC map shows Biden with 279 electoral votes, and NBC News' Mark Murray writes that while that math is "not impossible" for Trump, it is "daunting." Brendan Morrow

It turns out Sen. Ted Cruz (R-Texas) agrees with the Democratic presidential nominee, former Vice President Joe Biden, on at least one thing.

"One of Biden's best points," he said during an interview with Jonathan Swan that aired Monday night on Axios on HBO, "was when he said all of these attacks back-and-forth about [Biden's] family and [Trump's] family, they don't matter, what matters is your family. That may have been Biden's best moment, actually."

Cruz then told Swan he doesn't think the Trump campaign's last-minute push to focus on allegations of corruption against Biden's son, Hunter, "moves a single a voter." View more clips of Cruz's interview at Axios. Tim O'Donnell

With the presidential election a week away, Democrat Joe Biden is the clear favorite. Yet "all of us — Republicans and Democrats, journalists and party operatives, political junkies and casual observers — are held hostage by memories of four Novembers ago," when President Trump scored his huge upset, Tim Alberta writes at Politico. "The bad news for Trump supporters: 2020 is nothing like 2016."

"We know what those polls suggest," Peggy Noonan observed in The Wall Street Journal. "But there is little air of defeat among Trump supporters and no triumphalism among Democrats. Trump supporters believe he will win because of his special magic, Trump foes fear he will win because of his dark magic. Pollsters and pundits stare at the data and wonder how to quantify his unfathomable magic."

Real Time's Bill Maher is nervous about the election, too, "but it's not election night, it's Nov. 4 to Jan. 20, and then after," he told Jimmy Kimmel on Monday's Kimmel Live. "It's impossible to imagine, I think, Trump losing and then and then saying, 'Well, we fought the good fight but the best man won, and I'm telling my staff to graciously allow Biden to take over.' No, he's never going to do that. He's going to lose — my prediction. Now, last time I didn't even say Hillary was going to win, when most people did. This time I do think Biden's gonna win by large numbers, popular vote and even the Electoral vote, and then Trump is gonna go apes--t."

Trump "doesn't do losing — other than three marriages, three casinos, four magazines, an airline, a football league, a charity, and a university, he's never lost anything," Maher deadpanned. "So he's not going to go gently into the night. That's what I worry about. And he's a master of 'It isn't written down, so I can do it.'" Watch Maher's explanation of how that might work with the Electoral College below. Peter Weber

Researchers in the United Kingdom say they've observed a "significant" decline in the percentage of the population with COVID-19 antibodies, potentially pointing to "waning immunity."

Imperial College London scientists in the study found the prevalence of COVID-19 antibodies declined from six percent of the British population in June to 4.4 percent in September, Reuters reports. They came to the conclusion that there has been a "significant decline in the proportion of the population with detectable antibodies" by sending out finger-prick tests to a randomly selected group of over 365,000 people in England, according to CNN.

"On the balance of evidence I would say, with what we know for other coronaviruses, it would look as if immunity declines away at the same rate as antibodies decline away, and that this is an indication of waning immunity at the population level," Wendy Barclay, head of Imperial College London's Department of Infectious Disease, said, per Reuters.

The researchers were specifically looking for IgG antibodies in the study, and CNN notes that some other research has suggested "that other types of antibodies may persist longer than IgG does."

But Imperial College London's Helen Ward told BBC News the study suggests that "immunity is waning quite rapidly." Ward added in a statement, "We don't yet know whether this will leave these people at risk of reinfection with the virus that causes COVID-19, but it is essential that everyone continues to follow guidance to reduce the risk to themselves and others." Brendan Morrow