A 16-year-old migrant boy has become the fifth migrant child since December to die after being apprehended at the U.S. border.

Updated at 7:09 p.m. ET

A federal judge ruled against President Trump on Monday in a subpoena dispute not long after the White House said it is seeking to block its former top lawyer from talking to Congress.

The events amounted to a win — and a loss — apiece for Republicans and Democrats in their ongoing high-stakes legal and political war over separation of powers and oversight in the aftermath of special counsel Robert Mueller's investigation.

The McGahn matter

Ukraine now has a new president, as Volodymyr Zelenskiy was sworn into office on Monday — and the famous comedian immediately said one of his first actions will be to dissolve parliament. Fulfilling a campaign promise, Zelenskiy announced a snap election to choose new lawmakers.

From student loan debt to unaffordable housing to the opioid crisis, Democratic presidential candidate Elizabeth Warren has developed a reputation for having a policy plan for everything.

Bob Best enthusiastically supports President Trump's tough policies against China and other countries.

"I'm not a big tariff guy. I'm a free trade guy," says Best, who manages a heating and air conditioning company in Kennesaw, Ga.

"But sometimes when the bully just doesn't listen, you've got to punch him in the mouth. And that's what he's doing."

Zakary Pashak is a rare breed. His company, Detroit Bikes, is one of the very few American bicycle makers. Most bikes come from China.

At times, Pashak endured ridicule at trade shows. "I'd get kind of surly bike mechanics coming up and telling me that my products stunk. There's definitely a fair bit of attitude in my industry," he says.

But last September, the industry's tune abruptly changed. The first round of U.S. tariffs, or import taxes, upped the cost of Chinese-made bikes by 10%, and companies saw Detroit Bikes as a potential partner.