【Watch The War of the World】

Steve Kerr's Twitter account had been silent for more than a month before it erupted in a flurry of activity this weekend. The Watch The War of the WorldGolden State Warriors coach logged on and he most definitely did notstick to sports.

First, Kerr retweeted a powerful rebuke of Donald Trump's planned border wall from the mayor of Berlin on Friday. On Saturday, Kerr reposted criticisms of Trump policies. They came from sources as varied as The Onion, a New York Timescolumnist, an NBA veteran and a former official in the Obama administration.

SEE ALSO: My president was a hooper

"This is a must read," Kerr then wrote on Sunday, sharing an article with his 278,000 followers. It was piece from TheAtlantic, blasting what the magazine called Trump's "betrayal of American values."

On the surface, Kerr's spurt of social media activity wasn't a total surprise. The sports world as a whole has reacted with opposition to Trump's first several days as president. Figures from the NBA -- coaches and players alike -- have been particularly outspoken, both on social media and in interviews with reporters. All those who speak out are unique. All have individual reasons for doing so.

But the voices of two NBA figures -- Kerr and Gregg Popovich, coach of the San Antonio Spurs -- carry particular weight, thanks to their contrasting backstories.

When these two -- the man whose father was murdered by a terrorist, and the former active-duty Air Force officer -- speak, we should listen.

'It's shocking and it's a horrible idea'

Popovich, left, and Kerr, before a game in 2014. Credit: Jose Sanchez/AP/REX/Shutterstock

Kerr is one of the few who actually knows what it's like to have your life upended by terrorism.

The Warriors coach followed up his online activism this weekend by again criticizing Trump's wide ban on Muslim refugees and immigrants in a session with reporters Sunday. He prefaced that by saying he spoke "as someone whose family member was a victim of terrorism, having lost my father."

This Tweet is currently unavailable. It might be loading or has been removed.

"If we're trying to combat terrorism by banishing people from coming to this country, by really going against the principles of what our country is about and creating fear, it's the wrong way to go about it," Kerr said. "If anything, we could be breeding anger and terror, so I'm completely against what's happening. It's shocking and it's a horrible idea."

Mashable Top Stories Stay connected with the hottest stories of the day and the latest entertainment news. Sign up for Mashable's Top Stories newsletter By clicking Sign Me Up, you confirm you are 16+ and agree to our Terms of Use and Privacy Policy. Thanks for signing up!

Kerr was a freshman basketball player at the University of Arizona in 1984 when his father, Malcolm Kerr, a professor and president of the American University of Beirut, was shot to death outside his office. An Islamic extremist group later took credit for the killing.

The New York Timesreported at the time that Malcolm Kerr "was killed, his friends insist, not for being who he was, but because now that the Marines and the American Embassy in Beirut are smothered in security, he was the most vulnerable prominent American in Lebanon and a choice target for militants trying to intimidate Americans into leaving."

Steve Kerr has discussed his father's death and what it means to him before, but he opened up most recently and candidly in a Timesprofile from December. His father's death, the coach explained, still informs how he sees the world and relates to people. But he's hardly vengeful.

“Put yourself in someone else’s shoes and look at it from a bigger perspective,” Kerr told the paper. “We live in this complex world of gray areas. Life is so much easier if it could be black and white, good and evil.”

Meanwhile, when Popovich -- another vociferous Trump critic -- speaks out, his credibility comes from a different place.

Pop's past life

Popovich with the NBA's coach of the year trophy in 2014. Credit: Eric Gay/AP/REX/Shutterstock

Popovich ripped Trump as untrustworthy in an interview with reporters last week. But he didn't just speak as the coach who's led the San Antonio Spurs to five NBA titles -- he also spoke as coach of the U.S. men's national basketball team.

"We've got to a point where you really can't believe anything that comes out of his mouth," Popovich said of Trump last week, per ESPN's Rachel Nichols. "You really can't. All those thousands that were on the rooftops after 9/11? There were like two. And 'We went to Hawaii and checked (Obama's) birth certificate and investigators couldn't believe what they found! There wasn't anything there. That kind of thing." 

To recap, that's the coach of the U.S. national basketball team absolutely blasting the U.S. president's character -- an unusual dynamic, to say the least.

Popovich's flag-waving credentials go much deeper, too.

As noted by Nichols after his comments last week, Popovich is a graduate of the U.S. Air Force Academy who went on to serve five years of active duty beginning in 1970. He rarely discusses his military service, but the San Antonio Express-Newsdid some sleuthing into his previous life a few years back.

This Tweet is currently unavailable. It might be loading or has been removed.

This Tweet is currently unavailable. It might be loading or has been removed.

Kerr and Popovich aren't the only NBA coaches to take on Trump. They certainly won't be the last pro basketball figures to do so. But, like Luol Deng -- a current NBA player and former refugee who posted an Instagram message opposing Trump's ban on Monday -- they speak out for a reason.

These are people sports fans know for their exploits in basketball. But they're also human beings who've led lives that color well beyond the sports world's lines.

So why should we expect them to "stick to sports," most of all in times like these?

---

Featured Video For You

---

IKEA built a replica of a Syrian refugee home inside a store

---

Topics Donald Trump Politics