#TakeTheKnee trending hashtag reveals sharp debate over NFL players' kneeling Opponents and supporters of the player protests are using the hashtag.

 -- President Donald Trump's lashing out at NFL players who kneel in protest during the national anthem, and the reaction is playing out in part on social media, including under Twitter hashtags #TakeAKnee and #TakeTheKnee, which were trending Sunday morning.

The hashtag drew sharp responses from people both opposed and supportive of players protesting by kneeling during the pregame national anthem, a practice that drew attention beginning in the 2016 preseason when Colin Kaepernick, then a quarterback for the San Francisco 49ers quarterback, quietly knelt. Kaepernick told the press he was protesting the treatment of blacks in the United States.

One supporter of the protests said that critics should "wake up" because the players are exercising their rights.

Katie Hopkins, a controversial British columnist and a former reality star, focused her criticism on Kaepernick.

California Rep. Ted Lieu, a Democrat who has been critical of Trump, said the president has "no moral standing" to call for NFL players to be fired for kneeling in protest.

Jack Posobiec, a well-known right-wing activist who has promoted conspiracy theories like "Pizzagate," argued that 80 percent of Americans tuning into NFL football today would turn off the TV if players kneel during the anthem.

Dinesh D’Souza, a conservative political pundit, called for fellow opposers to boo the teams and players that refuse to stand during the anthem.

It's time to loudly boo teams & players who refuse to respect the national anthem--we too can exercise our right to protest #TakeAKnee

One opponent of the silent demonstration by players posted a picture of a sign suggesting that some locales may want to stop airing NFL games if the player protests continue.

A supporter of the protest actions called for all NFL players to take a knee.

Another who is opposed tweeted an image of a U.S. military service member kneeling at a grave.

One Twitter user, who claimed to be a veteran, said his service was so "football players could take a knee during the anthem to protest injustice."

A Twitter user argued that taking a knee "has nothing to do with the flag," and posted a list of African-Americans who died in incidents involving police.