The Note: Erosion in base underscores debate’s stakes for Trump

The TAKE with Rick Klein

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 that's enough to potentially matter in Pennsylvania, 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.

The RUNDOWN with MaryAlice Parks

Both candidates head into Tuesday's debate aware of Biden's eye-popping and consistent lead among women.

Their push to female voters will be key to watch and crucial for both men to get right.

Trump has to stop the bleeding. In Tuesday's ABC News/Washington Post poll, Biden led women by 23 points and suburban women specifically by 18 points. The stat could make it harder for Trump to take a victory lap and celebrate his Supreme Court nomination over the weekend.

Biden might be at times shier talking about women's reproductive rights compared to other Democrats, but the issue for Trump could be real doozy.

Sure, Judge Amy Coney Barrett, a staunch social conservative, excites his base, but a long and drawn-out conversation about repealing Roe v. Wade or the Affordable Care Act right before Election Day could cement needed independent women for Biden.

The TIP with Allison Pecorin

There's little Democrats can do to stop the Senate from voting to confirm Barrett to the Supreme Court, but that doesn't mean they won't snub her along the way.

Senators typically meet with SCOTUS hopefuls before their confirmation, but on Sunday, Senate Minority Leader Chuck Schumer said he would not meet with Barrett. Sen. Kirsten Gillibrand, D-N.Y., followed his announcement tweeting she would also skip a meeting, and spokespeople for Sens. Bob Casey, D-Penn, and Mazie Hirono, D-Hawaii, have also confirmed they don't intend to share face time with the judge.

This move comes straight from the playbook of Mitch McConnell, who in 2016 led his party in almost unanimous refusal to meet with President Barack Obama's 2016 Supreme Court nominee.

But don't expect all Democrats to follow along. Sen. Dick Durbin, D-Ill., told ABC News on Sunday that he would meet with Barrett. She is expected on the Hill Tuesday for meetings with McConnell, Judiciary Chairman Lindsey Graham and other members.

ONE MORE THING

Overwhelming support in Philadelphia and its suburbs lift former Vice President Joe Biden to a clear lead in crucial Pennsylvania, with backing from college-educated white people and women -- notably white, moderate and suburban women -- central to his advantage in a new ABC News/Washington Post poll. President Donald Trump, for his part, is suffering attrition among his 2016 supporters; 8% of them now back Biden instead. While a small slice of the electorate, it's a potentially important factor in a state Trump won by 44,292 votes out of nearly 6.2 million cast four years ago.

THE PLAYLIST

ABC News' "Start Here" podcast. Tuesday morning's episode features ABC News Chief Global Affairs correspondent Martha Raddatz, who tells us 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. FiveThirtyEight's Galen Druke explains how the debate could sway voters. And ABC News' Kayna Whitworth joins us from the fire line as Santa Rosa, California, deals with fresh fire dangers. http://apple.co/2HPocUL

FiveThirtyEight Politics Podcast. The New York Times reported on Sunday that President Donald Trump paid $750 dollars in federal income taxes in 2016 and 2017, and no federal income tax during 10 of the previous 15 years due to reported business losses. In this installment of the FiveThirtyEight Politics podcast, the crew weighs the potential political implications of the report. They also discuss what a 6-3 conservative majority on the Supreme Court would look like, given Judge Amy Coney Barrett's nomination to replace Justice Ruth Bader Ginsburg. https://53eig.ht/3kT4bvo

WHAT YOU NEED TO KNOW TODAY

• Senate Democratic Leader Chuck Schumer appears on ABC's "The View."
• The first presidential debate between President Donald Trump and former Vice President Joe Biden will air commercial-free from 9 to 10:30 p.m. ET on ABC and stream on ABC News Live. Pre-show coverage will begin on ABC News Live at 7 p.m. and on the network at 8 p.m. Following the debate, there will be additional analysis on ABC and ABC News Live.
• A special election will be held to fill Georgia's 5th Congressional District seat, left open after Rep. John Lewis' death.
• Judge Amy Coney Barrett will begin to make Senate courtesy calls. Barrett is meeting with Senate Majority Leader Mitch McConnell and Vice President Mike Pence at 10 a.m., with Sen. Mike Crapo at 11 a.m., Sen. Chuck Grassley at 1 p.m., Sen. John Thune at 3 p.m. and Sen. Mike Lee at 3:45 p.m. She meets with Senate Judiciary Committee Chairman Lindsey Graham at 5:30 p.m. Barrett is also expected to meet with Republican Sens. Ted Cruz, Cory Gardner and Tim Scott.
• Pence also leads a White House Coronavirus Task Force meeting at 2 p.m. and travels to Pennsylvania to host a campaign event and presidential debate watch party in Lititz at 7 p.m.
• Trump travels to Ohio in the afternoon.
• Former second lady Jill Biden travels to Michigan. She tours a farm in Central Lake to hear about how climate change is impacting farmers at 1 p.m. and will be joined by Chasten Buttigieg at a voter mobilization event at 2:30 p.m. in Traverse City.
• Sen. Kamala Harris, D-Calif., attends a virtual Biden for President finance event.

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The Note is a daily ABC News feature that highlights the key political moments of the day ahead. Please check back tomorrow for the latest.