As a new National Football League season prepares to kick off Thursday night, a majority of Americans, including a majority of football fans, say it is acceptable for professional athletes to kneel during the national anthem, and an even larger percentage say athletes should use their platforms to tackle social issues, according to a Washington Post poll.

This summer, as widespread protests over racism and police violence roiled the nation, athletes across every major American sport have become increasingly vocal on social issues. They have sat out events, protested during the anthem and pushed for policy changes around policing, voting rights and other issues. While athlete activism promises to take center stage this week — starting with Thursday’s opener in Kansas City, Mo., and continuing through the full slate of NFL games this weekend — 56 percent of Americans now say it is appropriate for athletes to kneel during the national anthem to protest racial inequality; 42 percent say it is not appropriate.

Despite cries for athletes to “stick to sports,” particularly from conservative pundits and politicians, a 62 percent majority of Americans say professional athletes should use their platforms to express their views on national issues, including over 8 in 10 Black Americans and 7 in 10 adults under age 50.

Opinions are similar among football fans, with 59 percent saying kneeling during the national anthem is an appropriate way to protest racial inequality and 64 percent saying athletes should express views on national issues in general.

The results underscore an ongoing shift in the way much of the country views the anthem protests that shook the NFL four years ago when quarterback Colin Kaepernick first took a knee to protest police brutality and systemic racism. Dozens of players across the league followed his lead, upsetting large factions of fans and stoking a political fight about the role of athletes. Even two years after Kaepernick first knelt, a 2018 NBC-Wall Street Journal poll found that 54 percent of registered voters felt professional football players kneeling in protest was inappropriate and 43 percent felt it was appropriate.

Though most of the games this weekend will be played in near-empty stadiums because of the novel coronavirus pandemic, players across the league have been mulling whether and how they might protest during the NFL’s opening week, the league’s first live action since the protests began in May.

With just over 2 in 5 Americans still objecting to anthem protests, the issue has become a popular subject on political campaign trails, galvanizing some voting blocs and stirring strong feelings about patriotism, the military and policing. The NFL has been criticized at times for struggling to support players attempting to demonstrate and appeasing fans angered by the kneeling — including one prominent critic who has spoken out often on the issue.

“Looking forward to live sports, but any time I witness a player kneeling during the National Anthem, a sign of great disrespect for our Country and our Flag, the game is over for me!” President Trump tweeted in July, one of eight tweets devoted to the issue in the past three months.

The latest poll results echo a July NBC-Wall Street Journal poll that found 52 percent of registered voters felt it was appropriate for athletes to kneel in protest. And they come at a time when the NFL and many individual teams also have begun to take a softer stance on anthem protests and voice support for athlete advocacy.

NFL Commissioner Roger Goodell said last month he wishes “we had listened earlier” to Kaepernick, who has been out of the NFL since 2017, and the league has said it will not punish players who opt to protest this season.

“This is a peaceful protest, and we’re going to support them if they choose to do that," Goodell told NBC’s Peter King last week.

Following the lead of the National Basketball Association and Women’s National Basketball Association, which emblazoned “Black Lives Matter” on their courts this season, the NFL will paint the phrases “End Racism” and “It Takes All of Us” in end zones at NFL stadiums.

Players will wear decals on their helmets this season with the names of victims of police brutality. The league and individual teams also have spoken out in support of specific social and political causes in recent weeks.

The league surely will hear from fans whose feelings on the anthem protests have not budged. Just the prospect of player demonstrations sparked backlash this week. At the possibility that Dallas Cowboys players might protest, Eric Trump, the president’s son, tweeted: “Football is officially dead — so much for ‘America’s sport.’ Goodbye NFL ... I’m gone.”

According to the Post poll, the majority of Republicans and people over the age of 50 call kneeling during the national anthem “not appropriate.” The feelings are particularly divided along partisan lines. Majorities of Democrats (73 percent) and independents (54 percent) say it is appropriate to kneel during the anthem in protest, while 36 percent of Republicans say it is appropriate. While a 63 percent majority of Republicans still say it’s inappropriate, opposition to anthem protests has fallen among Republicans and independents. In the 2018 poll, 88 percent of Republican voters said it was not appropriate. Independents flipped from 57 percent saying an anthem protest was inappropriate two years ago to 54 percent saying it is appropriate in the new Post poll.

Among Black Americans, 72 percent say it’s appropriate to kneel during the national anthem in protest of racial inequality, compared with 52 percent of White adults and 59 percent of Hispanics. And over 8 in 10 Black Americans (82 percent) say athletes should use their platforms to express their views along with smaller majorities of Hispanic (70 percent) and White Americans (56 percent).

In the wake of George Floyd’s killing at the hands of a Minneapolis police officer in May, athletes in all major sports began speaking out, taking on social causes and helping shine a spotlight on racial inequality and police brutality. NBA squads halted their playoffs last month and postponed games to protest the police shooting of Jacob Blake in Kenosha, Wis., and other leagues — including the WNBA, the National Hockey League and Major League Soccer — followed suit.

Many of the sports world’s biggest stars have become outspoken advocates, including LeBron James, Serena Williams and Megan Rapinoe. In addition to on-field protests and concerns voiced in interviews and through social media, many have begun to support voter turnout efforts and have pointed fans to organizations promoting social justice and, in many cases, the Black Lives Matter movement.

This outspoken advocacy has drawn a large rebuke from some fans and political leaders, and the Post poll finds that feelings are sharply divided along political lines. Eighty percent of Democrats and 60 percent of independents say pro athletes should use their platforms to express their views, while 57 percent of Republicans say they should not.

The poll also finds that young people are especially open to athletes protesting and taking on social causes. By nearly a 2 to 1 margin, Americans under age 50 say it is appropriate for athletes to kneel during the national anthem, while over half of those 50 and older say it is not appropriate. While 7 in 10 Americans under the age of 50 support athletes using their platforms to discuss non-sports matters, 55 percent of those 65 and older say the athletes should not publicly share their views.

According to the poll, Americans’ opinions about whether athletes should express themselves on these issues are closely tied to their concerns about police treatment of Black Americans.

Six in 10 Americans say recent killings of Black people by police are a sign of broader problems in the treatment of Black people by police, according to the poll, while 36 percent say they are isolated incidents. That’s roughly similar to a July Post-ABC poll, which found 55 percent of Americans saying the killings of unarmed Black people were a sign of broader problems, though down from a Post-Schar School poll in June that found 69 percent saying Floyd’s killing was a sign of broader problems.

Among those who say police killings of Black people are “a sign of broader problems in the treatment of Black people by police,” 78 percent say athletes should use their platforms to express themselves. But support for athletes speaking out on national issues drops to 37 percent among those who view police killings of Black people as “isolated incidents.”

The Post poll was conducted Sept. 1-6 among a random national sample of 1,001 adults, with 70 percent reached on cellphones and 30 percent on landlines. Overall results have a margin of sampling error of plus or minus 3.5 percentage points. Results among Black adults include the small share who identify their race as Black but their ethnicity as Hispanic.

Scott Clement contributed to this report.