The Democratic presidential aspirants breathing down Joe Biden's neck

This week Democratic Governor Gavin Newsom reserved more than $100,000 in television advertising in Florida.

It's not a significant sum for a governor running for re-election in a large American state.

But what raised eyebrows is this: Newsom is the governor of California, on the opposite side of the country.

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The baffling decision has led to serious speculation that Newsom is going to run for president in 2024.

The problem is, Joe Biden is from the same party as Newsom, and has said repeatedly he will run for re-election.

Typically presidents have the close-to-unanimous backing of their own parties to run for their second term in office. 

But Biden is historically unpopular and has shown little capacity to address the inflation crisis that has gripped America.

He is especially unpopular among younger Americans, the age group his party relies on the most to win elections.

And there's the other big concern - Joe Biden is 79-years-old, and isn't getting any younger.

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Newsom, by contrast, is a young looking 54 years of age.

And recently, Newsom has started weighing in on national affairs like abortion, climate change and gun restrictions.

Newsom a resume that speaks to his progressive politics.

As mayor of San Francisco in 2004, he ordered the city clerk to issue marriage licences to same-sex couples, making his the first jurisdiction in the country to do so.

He ended the death penalty in his state and has proposed a plan to allow out-of-state residents to come to California for free abortions.

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Newsom isn't the only Democratic governor working on building his national profile.

In the midst of his own re-election fight, Illinois Governor JB Pritzker flew out to New Hampshire to address that state's Democratic annual convention.

New Hampshire is the first state in the nation to hold a presidential primary, and winning over voters there is key to gaining momentum in the race.

But there's no reason for an Illinois politician to visit New Hampshire unless they are looking to end up in the White House.

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It's a reality even locals in New Hampshire are proud of.

Pritzker regaled the crowd with his own scathing anecdotes about Donald Trump, before they gave him a standing ovation.

"I think he should be our next president," New Hampshire local Democratic official Johnna Davis told Politico after Pritzker's speech.

"He's got great energy. He's perfect."

Meanwhile, Michigan governor Gretchen Whitmer may be looking to Washington next as she appears set to cruise to re-election in the must-win presidential state.

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If any or all of these candidates jump in the race to challenge Biden, it may be enough to coax him into retirement.

Lyndon Johnson did the same thing in 1968 as his popularity declined as the Vietnam War dragged on.

If Biden does retire, it opens up the race for a couple of other heavy hitters.

Vice President Kamala Harris is constitutionally the next-in-line for the presidency, and would certainly jump into the race if Biden steps aside.

Transportation Secretary Pete Buttigieg would also likely run, using his cabinet position to bolster his previously thin resume.

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Buttigieg would have to quit his current job to run.

It is unlikely any of these people will jump into the presidential race until after the midterm elections in November.