The nationwide US protests for racial justice are giving Joe Biden, sidelined for over two months by the coronavirus pandemic, the opportunity to reclaim the spotlight and display a contrasting leadership style to that of his November election opponent President Donald Trump.

"This is very much a tale of two types of leadership skills," said Capri Cafaro, an executive in residence at American University in Washington. "What strength looks like to these two men is very different."

"Trump tries to position himself as making leadership synonymous with strength and strength synonymous in this context with the use of military force," said Cafaro, the former Democratic minority leader of the Ohio Senate.

For former vice president Biden, "leadership and strength are more synonymous with 'soft power,' if you will -- collaboration, listening, engagement," Cafaro said.

Hakeem Jefferson, an assistant professor of political science at Stanford University, said issues of race and justice were always going to be prominent in the campaign even without the protests sparked by last week's death of George Floyd, the black man killed by a white police officer in Minnesota, and the crackdown ordered by Trump.

"This is a function of having an incumbent president, Donald Trump, who came to power stoking racial fears, inciting and giving comfort to racial violence," Jefferson said.

Biden, in his first major public speech since going into isolation in mid-March because of the virus outbreak, called Floyd's death a "wake-up call for our nation" and accused Trump of turning the US into a "battlefield riven by old resentments and fresh fears."

The 77-year-old Biden, who served as deputy for eight years to America's first black president, Barack Obama, pledged to tackle "systemic racism" if elected to the White House.

"The country is crying out for leadership," he said. "Leadership that can unite us. Leadership that can bring us together."

- 'LAW & ORDER' -

Trump responded to Biden's remarks with a bellicose tweet.

"Weakness will never beat anarchists, looters or thugs, and Joe has been politically weak all of his life," the Republican president said. "LAW & ORDER."

Cafaro said the protests may have a greater impact on the election than the pandemic in that they provide Biden with the chance to "starkly contrast himself, his experience, his leadership and, his empathy with that we've seen thus far from Donald Trump."

At the end of the day, however, she said the recent events were unlikely to have much impact on hardcore supporters on either side.

"The base on the left and the right -- Trump's base and the Democratic base -- I don't think there's a lot of moving," she said.

"But there are a lot of independents on both the center left and the center right who are watching this as a flashpoint in our history, where you have the overlay of a pandemic, historically high unemployment and racial upheaval," she said.

Stanford's Jefferson said that while most black voters were indeed likely to cast their ballots for Biden in November they don't look at him as the "Savior."

He pointed to then-senator Biden's support for the 1994 "tough on crime" bill which is seen as having contributed to a wave of mass incarceration of African-Americans.  

"I think black folks are reminded of the choice that we have in November -- to keep in power a guy who gives comfort to white supremacists, who traffics in racist rhetoric," he said. "I think that's an easy choice for most black voters."

Jeffrey Grynaviski, a political science professor at Wayne State University in Michigan, said the election is likely to be a "turnout battle" -- decided on which party can mobilize more voters.

Grynaviski noted that African-Americans turned out in much smaller numbers for Hillary Clinton in 2016 than they did for Obama, and the question is whether they will go to the polls for Biden.

"My inclination is to say that Donald Trump's rhetoric over the last week is probably going to promote black support for Biden," he said, although his history with the crime bill works against him.