Trump led with the group by nine points in 2016, but is now trailing with the group by 27 points -- even in conservative corners of the country -- according to polling data.
Senior citizens like Tom Moran say the president has inspired him to become an activist in recent weeks. The 65-year-old is unable to work as a school bus driver because of the COVID-19 pandemic, and is now making it his mission to drive himself and his message across the country.
Moran drove thousands of miles to attend the vice presidential debate in Utah, and the presidential debate this week in Tennessee. At the latest, he held up a large banner that read, "220,000 DEAD. COVID-19. TRUMP FAILED US."
The Michigan resident will tell anyone who will listen that being away from his grandchildren this long didn't have to happen.
"They're 1 and 3," he said of his grandchildren. "My wife and I haven't seen them in six months. For a 1-year old, that's half of his life. President Trump has given up on the virus. He's quit. He's a failed president."
According to the Centers for Disease Control and Prevention, roughly 164,000 Americans who died from the virus are senior citizens. Those numbers may be influencing how red regions, like Sun City, in Arizona, (an affluent 40,000-person retirement community which is now showing major cracks) are voting. Recent polls have Biden neck and neck with Trump among seniors in the state.
Former Vietnam veteran and lifelong Republican Ben Harold said he'll vote Democratic for the first time, in this election.
"The Republican Party left me once I saw what Trump was doing. I could no longer support him," Harold said.
Harold now supports his local Democratic club, a group whose membership has tripled in size since Trump took office.
"It's his policies," said club president Marsha McGovern.
She added that the president's polls plunged as people got sick. "Two of my neighbors... were admitted to the hospital and then both died. And I think that just made us wake up and realize it doesn't matter what he says," McGovern said of Trump.
In The Villages, a retirement community in one of the most conservative pockets of battleground Florida, some seniors still firmly support Trump, while others are backing Biden.
"He's running this country like a business, and before the COVID came in, everything was right on target, and everything was great. And I feel as though he'll bring us back after this," said resident Cathy Slattery.
Al Meyer, another resident, said, "I think people are taking the opinion that they have the smarts to make a decision on what they want to do in order to protect their health. So I think the president has done a good job in that regard."
Seniors make up 82% of coronavirus deaths in Florida and about 78% nationwide. And while many voters are still undecided, recent polls show Biden is winning over seniors in the Sunshine State.
"We haven't gone out to sit in a restaurant since March. We stay pretty much at home. We stay with people we know," said resident David Grimes, a Biden supporter. "This is an administration that seems to say one thing and do something else. They say they value life, but they don't value elder life."
Senior citizens, key to Trump's 2016 victory, now far from a sure group for president