Can gaffe-prone Biden, 81, avoid flubs, freezes, falls, teleprompter slip-ups and booing Republicans to prove he IS fit for a second term in the most consequential State of the Union of his career...in front of the millions deciding between him and Trump

President Joe Biden has spent the past five days preparing for his State of the Union address, trying to cover all the possibilities: tea to keep his throat smooth, a print out of his remarks - with giant type – in case the teleprompter goes out, and hours of practice sessions.

But the fear among aides is all the preparations could be overshadowed by the unexpected: hecklers in the form of Republican lawmakers, a presidential freeze during the remarks, or, the worst case scenario, Biden trips walking up the aisle of the House chamber.

That would retrigger all the questions about the 81-year-old's fitness for office. And it would happen in front of millions of television viewers who are deciding whether to support Biden or his rival Donald Trump in the 2024 election. 

President Joe Biden gives his State of the Union address on Thursday night - above the president giving his 2023 speech

His staff is projecting confidence.

'The president's got this,' White House press secretary Karine Jean-Pierre said at her Wednesday press briefing.

The State of the Union address takes place in the shadow of the presidential race. The two nominees are decided. Voters know who their choice is. And Trump will on his Truth Social Thursday night, offering commentary about his opponent's remarks. 

Biden's re-election team is aware that the prime time State of the Union address will provide a huge platform for the incumbent president to make his case for a second term.

They are particularly targeting undecided voters and supporters of Nikki Haley, who dropped out of the Republican primary contest on Wednesday. Exit polls showed many voters who picked Haley were actually voting for someone other than Trump.

That gives the Biden re-election campaign hope they can win over those voters. 

What they need to be wary of on Thursday night, however, is that many voters won't see the entire State of the Union address - they'll see clips. And that could magnify a great Biden line or a massive stumble. 

'Voters for the most part, don't watch complete speeches, but they do watch clips,' said Timothy Naftali, a clinical associate professor at Columbia University.

'In this tiktok world, people are actually going to be looking at at segments and clips,' he noted. 

With the new mantra for staff being to let 'Joe be Joe,' sometimes being Joe means the president mixes up the names of world leaders, inserts random ad libs that are off topic, and gives snappy retorts to things he doesn't like.

President Biden reading over the text of his 2024 State of the Union speech in this photo posted by the White House

Donald Trump said he will provide commentary during Biden's speech on his Truth Social account

The pressure will be on Thursday night and not just because of November's presidential election. 

The speech will take place in the House chamber on Capitol Hill and the audience will be filled with Republican lawmakers loyal to Trump. 

And it could get rowdy.  

The White House points out how well Biden handled himself at last year's speech, when he quickly clapped back at Republicans' booing him for his claim they wanted to cut Social Security and Medicare.

As GOP lawmakers started heckling him, Biden quickly pivoted to say: 'As we all apparently agree, Social Security and Medicare is off the books now.'

In fact, House Republican Speaker Mike Johnson has asked his lawmakers to keep it reined in during the president's remarks.

Johnson, at a closed-door GOP conference meeting Wednesday, called for 'decorum' toward the president, Axios reported.

Overall, the goal of the White House is to present Biden, 81, as energetic enough to do the job and turn questions about his age into an argument for his experience. 

'He's got one to counteract the stereotype of the old man that Trump uses to critique him and to energize his own people, particularly young people who have real doubts about him, to get out to vote,' Naftali said.

Aides have long been trying to counter perceptions about the president's age. Many times Biden uses the lower stair case to board Air Force One, which has fewer stairs. He has tripped on the big staircase - twice.

He has been wearing sneakers, a more stable footwear, than his dress loafers when he travels. He prefers black Hokas. 

He even had them on during an event at the White House on Tuesday, a rare sighting as he usually wears dress shoes inside the complex. He likely hadn't changed out of them from earlier in the day when he had traveled from Camp David on Marine One.

His workout routine includes exercises to help his balance and his stiff gait. 

Biden aides hope the president avoids any major gaffes and doesn't fall - like he did above in June 2023 at the Air Force Academy Graduation Ceremony

Biden's 2023 State of the Union address where he was heckled by Republicans

The president has been closed up with aides working on the speech, which will reiterate his past accomplishments, lay out his agenda for the year and get in a few digs at Trump.

He had no public events on his schedule for Wednesday. 

And he spent the weekend shut up in Camp David working on his remarks with his senior staff: White House deputy chief of staff Bruce Reed, longtime aide Mike Donilon, communications adviser Anita Dunn, chief of staff Jeff Zients, counselor Steve Ricchetti, and speechwriter Vinay Reddy.

In the prep sessions, Biden goes through text, marking up words and creating breaks to remind himself to navigate around the stutter he has had since childhood, the New York Times reported. 

He will cut passages he doesn't feel like reflect his voice. 

He will touch on a variety of topics: the economy, taxes, reproductive rights, China, trade, immigration, the Israel-Hamas war, and the fighting in the Ukraine. 

Reproductive healthcare 'will be a key component of his remarks,' a senior administration official told reporters on a briefing call on Wednesday. 'He will focus on that freedoms of Americans are jeopardized.'

Democrats are using the abortion issue to rally their base after it was a successful battle cry for the party in the 2022 midterm election, where their candidates outperformed better than expected, largely thanks to abortion right issues on the ballot.

The president will also present a vision for the country that offers the stark choices facing the U.S. will be the propulsive theme of Biden's third State of the Union speech, his advisers told NBC News.

In his remarks, Biden will ask Americans if they want lower health care costs, democratic freedoms and to keep Ukraine from being swallowed up by Russian leader Vladimir Putin? Or do they want to side with drug company profits, tax breaks for the wealthy and Putin?

The underlying argument will be that Biden is on the right side of these issues, as opposed to Trump.

Biden will be editing his remarks up until he gives them.  A picture of the president, posted by the White House on its social media accounts, showed him with a binder of the text, the large type making his opening welcome easy to read.

After the president's speech, he and his team will spread out across the country to double down on their message.

Biden will go to Pennsylvania and Georgia. Vice President Kamala Harris will travel to  Arizona and Nevada. Other cabinet officials will travel to additional swing states, including Colorado, Ohio, Michigan, North Carolina and Tennessee.