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

The New York area has been the hardest-hit region in the United States during the novel coronavirus pandemic, but Gov. Andrew Cuomo (D) doesn't want his state singled out.

After President Trump said he was considering quarantining New York, New Jersey, and Connecticut on Saturday, Cuomo pushed back, calling the idea "preposterous" and a "federal declaration of war," while noting he didn't think it was even legal. Eventually, Trump said it wasn't necessary, but the Centers for Disease Control and Prevention issued a travel advisory, urging tri-state residents to refrain from non-essential travel for the next 14 days.

But Cuomo isn't completely satisfied — he said he still may sue Rhode Island if the state doesn't halt its new policy of stopping vehicles with New York license plates and collecting information about people who have traveled between the two states. Rhode Island Gov. Gina Raimondo (D) issued an order Friday empowering law enforcement to conduct those searches, and the National Guard will be stationed at airports and train stations for similar purposes. The National Guard will also knock on doors in coastal communities to identify anyone who has been in New York in recently to make sure they self-quarantine for 14 days.

Cuomo, though, thinks those precautions are "reactionary" and "illegal," but he is confident he and Raimondo can work out their differences "amicably" before getting the courts involved. Read more at CNN and The Hill. Tim O'Donnell

Former Vice President Joe Biden may have emerged as the leading Democratic presidential candidate because the party's more moderate bloc rallied around him, but now that the nomination looks likelier than ever, his campaign is making sure they don't lose support from the progressive wing come November, Politico reports.

"The dirty little secret is everyone's talking to Biden's campaign," said Sean McElwee, co-founder of liberal think tank Data for Progress. "There will be fights, but at the end of the day, progressives still hold votes in the Senate and increasingly Democratic voters stand behind our views. I expect we'll see Biden embracing key planks of the ambitious agenda progressives have outlined on issues like climate and pharmaceutical policy."

Most of Biden's support comes from older voters, so his team is trying to court younger generations who are more likely to back the policies MccElwee referred to. They're reaching out to groups like the climate-focused Sunrise Movement, as well as other organizations tied to gun control, immigration, and other issues. Most groups are committed to backing whoever the nominee is against Trump, but there is a sense that a lack of turnout among younger, progressive voters could hinder Biden if he's the nominee, making these efforts more crucial. And he may need to meet some expectations to convince people.

Evan Weber, the national political director for the Sunrise Movement, said their explicit support for Biden — compared to a broad anti-Trump campaign — depends on whether his campaign can "demonstrate that they are taking the climate crisis seriously." Read more at Politico. Tim O'Donnell

The U.S. government has begun to use cellphone data to get a better sense of people's movement in up to as many as 500 cities amid the novel coronavirus pandemic, The Wall Street Journal reports.

The tactic is not meant to track individuals, and names aren't included in the data, but instead is geared toward figuring out where people might be congregating in large numbers as calls for social distancing and lockdowns become the norm across the country. In doing so, the Centers for Disease Control and Prevention, in conjunction with state and local officials, hope to get an idea of how the coronavirus might be spreading so they can further curb its advance.

The data, which is coming from the less-regulated mobile advertising industry rather than cell phone carriers, could also provide information on whether people are complying with their area's shelter-in-place or stay-at-home orders.

Despite the intentions of the efforts, such projects will undoubtedly raise concerns about government invasion of privacy, and, while even some privacy activists understand the necessity of such efforts, they want stronger safeguards in place. Read more at The Wall Street Journal and read more about coronavirus surveillance here at The Week. Tim O'Donnell

Former Oklahoma Sen. Tom Coburn (R) died Saturday at his home in Tulsa after a long battle with prostate cancer. He was 72.

Coburn had battled health issues for many years, and his bout with cancer led him to retire from the Senate in 2015, two years before his second term was up.

An obstetrician by training, Coburn — who served in the House before winning a seat in the upper chamber — was known for his fierce commitment to conservatism, both fiscally and socially. He was opposed to the expansion of the federal government, abortion rights, and same-sex marriage, and did not believe in global warming science.

Still, the senator also was hailed for bipartisanship — he teamed up with former Sen. Carl Levin (D-Mich.) to issue a report on the 2008 financial crisis which accused Goldman Sachs and other powerful institutions of deception and greed. The Washington Post notes he gained the respect of many Democrats for his role in inquiries into corruption, tax avoidance, and fraudulent social security claims.

Levin said Coburn was a "terrific oversight partner in the Senate" thanks to the fact that he was "more interested in facts than politics." Read more at The Washington Post. Tim O'Donnell

While children certainly aren't immune to the dangers of the novel COVID-19 coronavirus, studies show they are at substantially lower risk of developing severe symptoms than adults.

That's rare when it comes to infectious diseases. Nicholas Christakis, a physician and professor of social and natural science at Yale University, points out that such diseases are the leading killers of children under the age of 5 around the globe each year. Yet, COVID-19 does not appear to be a contributor to the trend.

Christakis says scientists aren't sure exactly, but there are some theories developing. One possibility is that kids have more "adaptive" immune systems because they're still developing. Immune systems for adults are based more on memory, making them more susceptible to an unfamiliar virus, like the new coronavirus behind the pandemic. Along those lines, because many adults have built up immunity to other coronaviruses, their bodies might be overreacting to the virus.

Another dose of good news, Christakis surmises, is that children probably won't become more susceptible to severe cases of COVID-19 if it becomes endemic as they age, even if they lose some of the theoretical immunological protections that are present only in youthful systems. Tim O'Donnell

Journalists from three of the United States' most prestigious publications may not be able to report from China anymore, but Taiwan is offering them refuge.

Taiwan's Foreign Minister Joseph We invited American journalists from The New York Times, The Wall Street Journal, and The Washington Post, to set up shop on the China-claimed island after the newspapers were stripped of their credentials by Beijing. Wu said reporters from the prestigious U.S. publications would be welcomed with "open arms and lots of genuine smiles."

There reportedly aren't many permanent foreign correspondents stationed in Taiwan, and none of the three papers have a full-time presence on the island, so it remains to be seen if they'll take up the offer.

China announced earlier this month that it was revoking the papers' accreditations in their China bureaus, as well as preventing them from operating in Hong Kong. Beijing said the decision was retaliation for Washington labeling Chinese state media as diplomatic missions.

Taiwan has received praise for its handling of the novel coronavirus pandemic in part because the island has stepped up its border controls, mostly allowing entry only to permanent residences. But it seems they'd make an exception in this case. Read more at The Hill and Reuters. Tim O'Donnell