Trump's social media suggests a campaign scrambling from Biden leaving 2024 race

Former President Donald Trump and his campaign are reeling from the surprise announcement that President Joe Biden was ending his reelection bid, forced to pivot their infrastructure toward a new candidate as Trump himself airs out his frustrations publicly.

Trump campaign officials have publicly expressed confidence they can defeat any Democratic candidate; however, privately, sources have aired out frustrations surrounding new advertisement and messaging strategies.

Since Biden's announcement, Trump has taken to his social media platform to post more than 10 times, offering real-time insight into the changes Trump is going to have to make as he now has to prepare for competing against a new candidate, likely Vice President Kamala Harris.

The former president is still focusing much of his attacks on Biden, barely mentioning Harris, as he pushed unfounded claims that Biden isn't actually recovering from COVID, questioned how Biden would be able to serve the rest of his term, and even argued the Republican Party should be reimbursed for the money they've spent on challenging Biden.

"Crooked Joe Biden was not fit to run for President, and is certainly not fit to serve - And never was!" Trump first posted, continuing to post well into Sunday night -- then started up early Monday morning.

Though campaign officials have already started to pivot their focus to Harris, posting new ads and highlighting her gaffes, Trump unveiled the realities of the wasted money and resources the Trump team now has to deal with.

"Now we have to start all over again. Shouldn't the Republican Party be reimbursed for fraud in that everybody around Joe," he said in a post Sunday night.

Sources have complained to ABC News that they won't be able to use ads they had ready to go, including ones that highlighted Biden's poor debate performance.

It's unclear how much exactly the Trump campaign had spent on ads directly attacking Biden this election cycle, but pro-Trump super PAC Make America Great Again Inc., which has stricter disclosure requirements on ads than the campaign, had spent more than $30 million on ad placements attacking Biden.

However, the super PAC is already attacking Harris with several "flashbacks" using her own words in an attempt to remind voters on what they believe is a failed record -- rolling out a $5 million ad campaign in battleground states such as Georgia, Pennsylvania and Arizona.

In the immediate aftermath of Sunday's decision, it appears the Trump campaign and his allies' messaging is focused on linking the Biden administration's policies to Harris as well as criticizing Democrats for the unprecedented actions to the electoral process.

Given that much of Biden's campaign has been centered around labeling Trump a "threat to democracy," pointing to his legal cases and continuously highlighting the attack on the U.S. Capitol on Jan. 6, 2021. Now, Trump is flipping the argument, saying Democrats "stole" the race from Biden after primary voters chose him as the party's nominee.

"The Democrats pick a candidate, Crooked Joe Biden, he loses the Debate badly, then panics, and makes mistake after mistake, is told he can't win, and decide they will pick another candidate, probably Harris," Trump said. "They stole the race from Biden after he won it in the primaries — A First! These people are the real THREAT TO DEMOCRACY!"

Last week, Trump's vice presidential nominee Sen. JD Vance floated that if Biden doesn't seek reelection, then he should resign. Trump picked up this rhetoric following Biden's decision to step down saying, "If he can't run for office, he can't run our Country!!!"

"If Joe Biden can't run for president, he can't serve as president. And if they want to take him down because he's mentally incapable of serving, invoke the 25th Amendment," Vance said during a sit-down interview with Fox News' Jesse Waters taped on Saturday.

"You don't get to sort of do this in the most politically beneficial way for Democrats. If it's an actual problem, they should take care of it the appropriate way," Vance continued.

Trump, who clinched the Republican nomination for a third time at the Republican National Convention , suggested that the election was stolen in 2020. He classified his new campaign as competing for a "fourth time."

"Crooked Joe just got knocked out, so now I'll have to do it a FOURTH TIME!!!" Trump posted.

While Democrats try to lock in enough delegates for Harris to assume the top of the ticket in the coming days, the Trump campaign is forced to move forward with a new campaign strategy this week. It's a significant shift with a little more than 100 days until Election Day, in which Trump said he believed he would win by a "monumental landslide," picking up wins in battleground states and expanding the map to Minnesota, New Jersey and Virginia.