1st presidential debate between Trump and Biden spirals into chaotic clash

An immutable fact of politics in the era of President Donald Trump is that there's no separating the president from his base.

Yet an ABC News/Washington Post poll released Tuesday morning out of critical Pennsylvania -- FiveThirtyEight's most likely tipping-point state -- brings new evidence that Trump can't bank on the range of supporters he once did.

The poll shows former Vice President Joe Biden leading Trump 54-45 among likely voters, mirroring the results of the ABC/Post national poll released Sunday. Hillary Clinton backers from 2016 support Biden 98-1 in the Pennsylvania poll, while Trump's supporters from last time break 92-8 in his favor.

This does not mark a mass exodus. But it suggests a narrowing coalition, Wisconsin and Michigan -- all states won by Trump by less than a percentage point, in a region Trump and Biden are set to visit in the days after Tuesday night's first presidential debate.

There won't be many, or perhaps any, singular moments as critical as this first debate in terms of changing the trajectory of the race. Trump wants and needs to effectively disqualify Biden as an alternative -- to make the campaign about Biden more than himself.

Biden will be trying to avoid a brawl of an insult-fest. He will be seeking to keep the campaign focused on COVID-19 and the economy -- about Trump and his leadership, in a campaign that's been more steady than not.

-ABC News Political Director Rick Klein

ABC News Chief Global Affairs correspondent Martha Raddatz joins ABC News' Start Here podcast to talk about her experience moderating debates with both President Donald Trump and former Vice President Joe Biden before the two go head-to-head for the first time Tuesday night.

Ahead of tonight's presidential debate, a first opportunity to see former Vice President Joe Biden and President Trump spar over a range of critical issues, some voters already decided who they are voting for.

At least 1.1 million ballots have already been cast in the 2020 election, according to data compiled by Michael McDonald, an elections expert and professor of political science at the University of Florida.

Across the 14 state reporting data -- Minnesota, Michigan, Wisconsin, Florida, North Carolina, Georgia, Ohio, Iowa, Illinois, Virginia, South Carolina, Montana, South Dakota and New Jersey -- voters cast a total of 1,144,059 ballots, as of the most recent reports.

McDonald cautions that the total number is likely higher because he does not "have complete reports for all states."

On Sunday, when the vote total was just under 1 million, McDonald wrote in his analysis that the volume of early voters "this far in advance of an election has never occurred in any American election. Period."

"Around this time in 2016, I noted only 9,525 people had voted," he wrote. "There literally is no comparison since at this comparable point in time in 2016, so few people had cast early votes that states did not bother to release any data."

-ABC News' Kendall Karson

The horrific killing of George Floyd in March set off massive protests across the country against racial injustice and police brutality.

Over the months that followed, new and previous supporters of the Black Lives Matter (BLM) movement held demonstrations from coast to coast and a new generation of Americans protested for racial equality.

Race is now at the center of the national conversation heading into the final weeks of the 2020 campaign for president, from the disproportionate impact the novel coronavirus pandemic has had on communities of color to reforms that would help address racial disparities in policing.

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Trump vs. Biden on the issues: Racial justice

An overview of the presidential candidates’ positions on various issues.

It has also been a complicated issue for both candidates over the course of their long careers. Former Vice President Joe Biden made history by choosing a Black woman, Kamala Harris, to be his running mate and served alongside the nation's first Black president.

But he has also drawn criticism for his position on busing in the 1970's to help end segregation in schools and the 1994 crime bill, which helped lead to an era of mass incarceration.

Trump set the tone for his presidency when he said Mexico was not sending its best immigrants, including "rapists," on the day he announced his campaign. That was followed by a call to ban Muslim immigration, his perpetuation of the debunked "birther" conspiracy against President Barack Obama among other things. And he has largely ignored the sources of the racial unrest that has erupted around the country in recent months.

At the same time, Trump has claimed he is the least racist person and touted the economic opportunities he has created for African Americans during his presidency.

Here's a look at where Trump and Biden differ on the issue of racial justice, and significant statements they’ve made related to race

-ABC News' Justin Gomez