There wasn't a single question about global warming in the 2016 fall presidential debates. This time around, climate could be a dominant topic, Axios' Alexi McCammond writes.

• With climate-change evidence and awareness growing, some youth environmental activists say the worst thing to be as a Democratic presidential candidate is a "climate delayer" — someone who doesn't recognize the urgency.
• So the 2020 Democrats are under pressure to make climate a top issue.
• And the Democratic nominee will be sure to force the issue against President Trump, who's still denying evidence of a warming planet.

Even Washington Gov. Jay Inslee, who's running for president as the climate candidate, doesn't get a pass.

• Thirteen activists are suing Inslee and the state of Washington for "causing and contributing to climate change" by "promoting and implementing a fossil-fuel based energy and transportation system," said Andrea Rodgers, a lead lawyer on the case.
• Stephen O'Hanlon, communications director for the Sunrise Movement, said: "For too long people have patted themselves on the back for acknowledging that climate change is real but in effect ignoring the urgency and severity of the crisis."

The pressure has already had an impact. Six 2020 Democrats — Sens. Kamala Harris, Cory Booker, Kirsten Gillibrand, Elizabeth Warren, Amy Klobuchar and Bernie Sanders — are co-sponsoring the Green New Deal.

• Rep. Alexandria Ocasio-Cortez also paved the way for these demands on 2020 candidates by putting the Green New Deal on the national agenda. She told Rolling Stone: "We need moonshots."

"Born in the ashes of the financial crisis, Wall Street’s oldest-ever bull market turns 10 years old [today], with the S&P 500 tripling in value," Reuters reports.

• The index's post-crisis low close was 676.53 on March 9, 2009.
• Yesterday, it closed at 2,743.07.

"The S&P 500 has turned in a handsome annualized return of 15 percent during the bull market," per Reuters, "with the consumer discretionary and information technology indexes each up about 20 percent annually."

Russian internet trolls appear to be shifting strategy to disrupt the 2020 elections, promoting divisive messages "through phony social media accounts instead of creating propaganda themselves," Bloomberg's Alyza Sebenius writes.

• Russian hackers are trying to circumvent protections put in place by Facebook and Twitter after the 2016 election.
• "Instead of creating content themselves, we see them amplifying content," hiding behind someone else, said John Hultquist, director of intelligence analysis at FireEye.

Be smart: Hacked devices "are used to create many legitimate-looking users as well as believable followers and likes for those fake users."

Gayle King, co-host of "CBS This Morning," stayed poised as R&B star R. Kelly shouted, ranted and cried during his first interview since pleading not guilty to sexually abusing four females dating back to 1998, including three underage girls.

• "I could see him getting more heated," King told Stephen Colbert.
• "He was upset with me about some of the questions — that's OK. He was a little irritated, and that's OK."

"So when I see Robert [Kelly] getting really upset, and he stands out of his seat, my initial reaction was, 'Oh god, please don't leave, please don't leave," King continued.

• "If we had both gotten emotional and amped up like that, what good would have come of that?"

YouTube of the interview.

• Behind-the-scenes footage, with R. Kelly continuing to shout as makeup artists touch him up.

What's new: "[T]he enthusiasm that propelled Democrats to a decisive takeover of the House in the midterms is still surging, driving crowd sizes and intensity typically seen in the days before the first caucuses and primaries, not a year ahead of them," the N.Y. Times' Sydney Ember reports from Iowa City.

• Why it matters: Democratic voters are delighting in populist "calls to spurn big donors, the policies to fight wealth inequality and the promises of relief from college debt and steep medical bills."

Michael McDonald, an associate professor of political science at the University of Florida who studies voting data, said that in the general election, "We may see a hundred-year storm for turnout."

"Computers will be used for ball/strike calls starting April 25 in the independent Atlantic League," AP's Ronald Blum writes:

• "Plate umpires will wear earpieces and be informed of ball/strike calls by a TrackMan computer system that uses Doppler radar."
• "Umps will have the ability to override the computer, which considers a pitch a strike when the ball bounces and then crosses the zone."

Good news for humans: Joe West, who has umpired more than 5,000 big league games and is on track to break Bill Klem's record in 2020, said a past TrackMan test was spotty, missing 500 pitches in one month.

• "The beauty of baseball is that it's not foolproof," said West, who umpired his first big league game in 1976.
• "You've got to hit a round ball with a cylindrical bat square, and then you've got to get it past people. The game is typically American. It's always somebody else's fault when they lose — and usually it's [the umpire]."