By Sarah Mucha, CNN

(CNN) -- Joy Solomon is a retired businesswoman in Boca Raton, Florida, who voted for Donald Trump in 2016. But after watching the President's response to the coronavirus pandemic, she says she's voting for Democratic presidential nominee Joe Biden this time around.

"I'm going to tell you what turned me off the most. I was watching TV with the Covid, which I really think is a very serious thing, and I think he made it like it was no big deal," Solomon, 65, said.

"I think we lost control of the whole situation," she added. "And I can't forgive him for that. I just can't forgive him."

The Biden campaign is devoting significant resources to winning over more voters like Solomon -- senior citizens in Florida who might have backed the Republican nominee in the past but have been turned off by Trump's handling of the pandemic as well as his inflammatory rhetoric.

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So far, Biden's campaign has spent over $40 million on ads in the state, with several directly targeting older voters on the pandemic and Social Security. And it also hosts a variety of senior-targeted outreach events, like workshops teaching supporters how to write letters to the editor. Most recently, it hired a staff member devoted solely to senior outreach and organizing senior members of the community to vote.

That effort appears to be paying off. While Trump won Florida in 2016 with a double-digit lead over Hillary Clinton among voters age 65 or older, the latest polling suggests Trump's advantage with the group is gone, and at best for the President, Trump and Biden are close among Florida's seniors.

View Trump and Biden head-to-head polling

As Biden visits Florida Tuesday, he will land in a state where his campaign continues to underperform with Latinos compared to Hillary Clinton in 2016, which could make the senior citizen vote even more crucial to victory in a state that has been decided by less than two percentage points in the past two presidential elections.

"I think generally the Biden campaign is in better shape to win Florida than we were at this point either in '08 or '12," said Florida Democratic strategist Steve Schale, who worked on Barack Obama's campaign in the state during both election cycles. He also helps lead the pro-Biden PAC, Unite the Country. "I mean, obviously it has a long ways to go and in no way am I saying that it's anything but competitive, but I feel pretty good about things."

With the stakes high for both candidates -- no Republican has won the presidency without winning the Sunshine State since Calvin Coolidge in 1923 -- and the margins historically tight, the Biden campaign is targeting retirement community areas like The Villages, Sun City and Pinellas County that have high populations of senior citizens in hopes of peeling away some of the senior vote won by Trump in 2016.

"Knowing that the state is a 1% state, no matter what we do and how you slice it, seniors are always important and have been in past cycles. They make up so much of the vote that is a critical voting bloc for all of us," said the Biden campaign's Florida state director, Jackie Lee.

Frank Carlin, a retiree living in Florida's Tampa area, did not vote in the 2016 election. While he initially supported Trump, he changed his mind at the last minute but was "not high enough" on Clinton to cast his ballot. It's a choice he regrets, he says, and this year, it's different. Carlin, who is not affiliated with a political party, is all-in on Biden.

"Biden is like exhaling," he said. "It's like being in a storm, and I know calm waters are coming."

Messaging

The campaign released a series of ads in the last few months, three of which came out in a span of nine days, targeted directly at senior citizens, hitting the President on his handling of the coronavirus and accusing him of cutting Social Security.

In one ad, titled "Swing," a narrator begins: "Donald Trump stepped off the golf course and signed an executive action directing funding cuts for Social Security." Two ads center specifically on voters who live in The Villages.

In the month of September, the Biden campaign spent $16 million on ads in Florida, counting current reservations and spending during the first week, while the Trump campaign placed $13 million worth of ads. Florida is also the state in which the Trump campaign has invested the most this month. The most common theme across Biden's ads placed in Florida's main media markets in the last few months features a positive outlook toward the candidate, while the ads the Trump campaign has placed with the most frequency go negative against Biden.

The campaign's most-played ad in the state's main media markets, including Tampa and Orlando, since July, attempts to scare voters about the former vice president's views on policing, suggesting that a Biden presidency would result in 911 calls from senior citizens going unanswered, which is not true.

In the ad, an elderly woman notices an intruder in her home and attempts to dial 911 but is kicked to an automated voice messaging system. As the ad ends, the words "You won't be safe in Joe Biden's America" appear on the screen as the intruder makes his or her way into the home.

Biden drove the Social Security message home in an interview with a local Orlando station last month.

"Because look, in Florida, what's happening in Florida? I mean you have a President of the United States that just introduced a proposal to wipe out Social Security," he said, citing a letter from the Social Security Administration's chief actuary, who wrote that the entitlement's trust fund could be depleted by the middle of 2023.

Trump last month issued an executive measure allowing employers to defer the collection of certain workers' Social Security payroll tax until 2021, when it would be paid back. He said that if he wins, he would terminate the levy -- though it was unclear whether he meant the deferred amount or the payroll tax itself. Regardless, either step would take an act of Congress, which has indicated little interest in doing so.

At the request of four Democratic senators, the actuary found that completely eliminating the payroll taxes could deplete the Social Security trust fund in three years if no other revenue source were put in place. Trump has suggested that the money would come from the general fund, which also would require an act of Congress.

The actuary's analysis was based on hypothetical legislation that would not take money from the general fund.

"Social Security, it's a lifeline," explained Carlin. "If they would mess with Social Security in any way, even reduce the amount, it will cripple people down here."

He added, "If they mess with Social Security, I think you'd have a revolution with the people that are over 50."

The Trump campaign's special adviser for Florida, Susie Wiles, has called the Biden campaign's messaging regarding Social Security a "scare tactic."

"It's mythical," she said. "We know that the President has been very clear about his dedication to protect Social Security and Medicare."

Organizing efforts

Biden, who opted to forgo travel in the early throes of the pandemic, makes his first visit to Florida of the general election on Tuesday. Meanwhile, Trump, who became a full-time Florida citizen last year, has flown to there multiple times since March, on both official White House business and for campaigning purposes.

Trump's reelection campaign has also continued to physically knock on doors, a strategy the Biden campaign put on hold during the pandemic.

"Unlike the other campaign, we never stopped retailing on the ground," Wiles said. "There's not a mode of campaigning we don't employ."

The Biden campaign has argued that physical door knocking doesn't have a real impact on reaching voters and chooses instead to count a "quality conversations" metric. And in lieu of in-person events, one way the Biden campaign has been encouraging senior supporters to get involved is by sending letters to the editor in their local papers in favor of Biden. The campaign hosts regular virtual "training sessions" to teach seniors how to write letters based on topics they find important, and organizers teach the supporters how to place the letters.

Cris Andersen, a retired middle school teacher, moved to The Villages in 2014. While she was somewhat involved in the election in 2016, she has ramped up her efforts this year, and as an officer in the retirement community's Democratic Party, she has been working every day to teach people in her community how to vote by mail.

"After 2016, the way it turned out, I, like many people said, 'We gotta change this.' It can't happen again," she said.

So now Andersen works with a few dozen organizers to identify and call voters individually to remind them to vote. She and the other "coaches," as she said she likes to call them, sent fliers with reminders for community members to update their signatures and teach them how to make sure their mail-in ballot was received, among a number of priorities.

Andersen said her motivation comes from a combination of factors: disappointment in the quality of her retirement and desire to leave a good future for generations to come.

"I'm just passionate about making sure for my nieces and nephews and my great nieces and nephews that I leave the world better. I feel very committed to that," she said, adding, "And I'm also scared, you know, I don't think I'm at the end of my life, but that my retirement years -- it isn't what I'd hoped it could be."