The subpoena wars continue.

House Democrats on Tuesday gathered to to hear testimony concerning Special Counsel Robert Mueller's investigation into 2016 Russian election interference. But, for the second time this month, the witness did not show up. Former White House Counsel Don McGahn followed in the footsteps of Attorney General William Barr, who refused to appear before the House Judiciary Committee earlier in May.

McGahn was directly instructed by the White House to defy a subpoena for his appearance, based on a Justice Department opinion that his former role in the White House means he cannot be compelled to testify about his official duties.

House Judiciary Chair Rep. Jerrold Nadler (D-N.Y.) feels quite differently, however. He made that clear as the hearing, which went on — albeit briefly — even without McGahn. Nadler did acknowledge that McGahn did not "blindly" participate in unethical behavior during Mueller's investigation, but that doesn't mean he's off the hook when it comes to testimony. The congressman tossed aside the White House's stance on McGahn's obligation, arguing that he must show up, and that the Trump administration must cease its meddling in such cases altogether.

Ultimately the debate over whether McGahn must testify will be decided by the courts, Fox News' senior judicial analyst Judge Andrew Napolitano said on Tuesday. Tim O'Donnell

Stephen Colbert began Tuesday's Late Show with a few minutes of deadpan commentary on primaries, before hitting the day's big political news: "This afternoon, Joseph R. Biden officially announced that his running mate will be California Sen. Kamala Harris."

"This is an historic announcement, because Harris is the first Black woman and the first person of Indian descent to be nominated for national office by a major party," Colbert said. "So Trump's gonna have a hard time deciding exactly how to be racist about her." Biden was expected to pick a woman of color, he said, "but still, Sen. Harris is a surprising choice considering just how hard she went after him — I mean with hammer and tongs — over bussing, issues of racial equality."

"Say what you want about Joe, but the man went Black and he's not going back," Trevor Noah said at The Daily Show. "And I've got to say, I'm impressed that Biden picked Kamala even after she destroyed him at that debate. In fact, part of me thinks he only picked her so that she can just never dust his ass in public again. This isn't a VP pick, it's an insurance policy. And I'm really interested to see what the Trump campaign's line of attack is going to be on Kamala," he added, explaining how "everything she's done in her career appeals to Trump's base."

"Kamala is the daughter of two immigrants, she went to Howard University, she's a Democratic senator from California — that's an inspiring story, unless you're Trump, then it's a Stephen King novel," Jimmy Fallon joked at The Tonight Show. "She's only had the job for a few hours, but Kamala's already gearing up for her debate with Mike Pence — that's why she spent the entire day arguing with a mannequin at Kohl's." He tried out a Biden impersonation to illustrate how popular Harris might be.

"It was down to me and Kamala, but Joe wanted to go with someone who has 'experience,'" Sarah Cooper joked on Jimmy Kimmel Live. Like Harris, Cooper is the daughter of Jamaican immigrants, and while neither of her parents was born in India, like Harris' mother, her former employer, Google, evidently thought Cooper was Indian, not Black, she said, "because they kept promoting me." Cooper fielded personal questions from her fans, and she answered them all with her trademark Trump lip-syching. Watch below. Peter Weber

Dr. Anthony Fauci, the country's top infectious disease expert, expressed his doubts over Russia's claim that it has quickly created a COVID-19 vaccine that is safe and effective.

Russian President Vladimir Putin announced on Tuesday that his health ministry has approved a vaccine after just two months of trials. It "works effectively enough," he said, adding that his daughter has received a dose.

During a virtual panel discussion with National Geographic on Tuesday, Fauci said he hopes the Russians have "actually, definitively proven that the vaccine is safe and effective. I seriously doubt they've done that." There are several vaccine candidates being tested in the U.S. right now, Fauci continued, and "if we wanted to take the chance of hurting a lot of people, or giving them something that doesn't work, we could start doing this, you know, next week if we wanted to. But that's not the way it works."

The Russian vaccine has not gone through Phase III testing, when scientists compare the vaccine to a placebo in tens of thousands of people, The New York Times reports. This is not the time to cut corners, Fauci said, and Americans need to know that the U.S. isn't rushing to produce a vaccine "because we have a way of doing things in this country that we care about safety." Worldwide, there are more than 20 million confirmed cases of COVID-19, with at least 737,000 people dying of the virus. Catherine Garcia

Using a metal detector, an amateur treasure hunter made an incredible discovery in a Scottish field.

Mariusz Stepien was searching for objects near the village of Peebles, south of Edinburgh, when he found several items dating back to the Bronze Age, including jewelry and a sword. He told The Associated Press he began "shaking with happiness," and "felt from the very beginning that this might be something spectacular and I've just discovered a big part of Scottish history."

He was right. Archaeologists from the Scottish government's Treasure Trove Unit spent 22 days digging up artifacts from the field, and on Monday, they announced that this was only the second Bronze Age hoard ever excavated in the country. With Stepien and a few of his friends looking on, the archaeologists uncovered rings, buckles, the axle caps from a chariot, and a horse harness.

This was a "nationally significant find," Emily Freeman, the head of the Treasure Trove Unit, told AP. "It was an amazing opportunity for us to not only recover bronze artifacts, but organic material as well. There is still a lot of work to be done to assess the artifacts and understand why they were deposited." The items, as well as some dirt from the field, are now at the National Museums Collection Center in Edinburgh. Catherine Garcia

French Prime Minister Jean Castex is concerned that the country is going "the wrong way" when it comes to the coronavirus, as the number of new cases has almost doubled in the last 24 hours.

Since Monday, 1,397 new infections have been reported by France's health ministry and 14 people have died. During a press conference in Montpellier on Tuesday, Castex said the "epidemiological situation . . . is deteriorating," as "about 25 new clusters are identified every day compared to five three weeks ago."

A ban on gatherings of more than 5,000 people has been extended to Oct. 30, and Castex called on local authorities to also lengthen mask requirements. Nationwide, people must wear face coverings while inside government offices, stores, and on public transportation. Since the beginning of the pandemic, more than 30,000 people have died of the coronavirus in France. Catherine Garcia

Presumptive Democratic presidential nominee Joe Biden's pick of Sen. Kamala Harris (D-Calif.) as his running mate got a positive reception from Democrats. But what about the Republicans hoping to defeat President Trump this fall? Well, the GOP operatives behind the Lincoln Project approve, they signaled in a new ad released just hours after Biden announced his pick.

"Joe Biden is the president for this moment," the ad's female narrator says. "Standing with him, Kamala Harris, a strong voice for a better America. Daughter of immigrants, a passion for justice, a happy warrior in the battle for the soul of America. Joe Biden and Kamala Harris is the America we believe in, where hard work means more than family wealth, where compassion and kindness are strengths, not weaknesses. This is the America of our better angles. ... Joe Biden and Kamala Harris — it's time."

You can disagree with the Lincoln Project's politics — or not even really understand their politics — but you have to admire their speed. Peter Weber

Democratic Rep. Ilhan Omar won Tuesday's primary in Minnesota's 5th Congressional District, defeating four challengers, including one who received millions in donations.

Her closest challenger was Antone Melton-Meaux, a mediation lawyer who used the millions he raised to outspend Omar by a two-to-one margin on TV ads, Politico reports. The website Open Secrets, which tracks campaign donations, said more than $2.5 million was spent by outside interests in an attempt to defeat Omar.

Omar was first elected in 2018, along with three other progressive women of color — Reps. Alexandria Ocasio-Cortez (N.Y.), Rashida Tlaib (Mich.), and Ayanna Pressley (Mass.) — dubbed "The Squad." She faced criticism in 2019 from members of the left and right when she made comments about Israel that some called anti-Semitic; Omar later apologized. Catherine Garcia