President Biden's approval rating, the lowest for any U.S. president in the past 15 years, combined with former President Trump's sweeping win in the Iowa caucuses, serves as a bellwether ahead of the November 2024 general election – but political observers question whether it's too soon to assume a Biden-Trump rematch has been secured. 

Yet several politicos who spoke to Fox News Digital predict if a rematch doesn't happen, it will be because of Biden getting out of the race – not Trump failing to secure the nomination.

"A unique aspect of this presidential year is that there really is no primary season for either party. Biden has managed to keep challengers off the ballots and Trump's lead amongst GOP voters is astronomical. Trump's landslide in Iowa is a statement. And while the debates and this process is important for people to get to know the GOP talent bench, the fact is we are in the midst of the general election between Biden and Trump," Fox News contributor Tammy Bruce said. 

"Trump is going nowhere, but Biden still could be replaced, but the closer we get to Election Day the more unlikely it is to happen," she added. 

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Trump won all but one of Iowa's 99 counties, with former U.S. Ambassador to the United Nations Nikki Haley – who came in third place overall in the Hawkeye State – clinging onto Johnson County by one vote. After congratulating Haley and Florida Gov. Ron DeSantis – the second-place winner in Iowa – during his Iowa victory speech for "having a good time together," the leader of the "Make America Great Again" movement was back in New York on Tuesday. 

"Donald Trump’s crushing victory over his opponents in the Iowa caucuses isn’t quite enough to wrap up the Republican nomination before the first primary contest has even taken place. But it very nearly is," Fox News contributor Gerry Baker said. "The results confirmed the grip the former president has on GOP primary voters." 

Baker, who is in Davos to attend the World Economic Forum, further surmised of the Iowa caucuses that "the third-place finish for Nikki Haley, who seemed to have some momentum heading into Iowa but who now must score a victory in New Hampshire next week to keep the race alive at all, underscored how far behind she and Ron DeSantis have always been." 

"So Trump is set to wrap things up quickly and will then be free of GOP opposition to concentrate his fire on Joe Biden," Baker said. 

"This only adds to the escalating bad news for Biden, already struggling with some of the lowest approval ratings for any president in recent history. With an uncertain economic outlook, chaos at the border and rising insecurity in the world, Biden faces overwhelming headwinds," he said. "Don’t be surprised if the calls within his own party for him to stand down and for a Democratic nominating contest to take place at this summer’s convention grow much louder." 

Biden’s approval rating sits at just 33%, according to a new ABC News/Ipsos poll released Sunday, a day before the Iowa caucuses, meaning the incumbent Democrat has the lowest approval rating of any U.S. president since George W. Bush from 2006-2008. Trump’s lowest as president was 36%. 

"If you're a Democrat, this is near a worst case scenario in a presidential election year. Here you have an incumbent president that's polling in the 20s as far as approval among Independents. He is hemorrhaging support from Black and Hispanic voters. No president has won re-election with approval below 40%, Biden is currently at 33% overall," Fox News contributor Joe Concha assessed. "Meanwhile, Donald Trump just won Iowa by more than four touchdowns over a popular governor and formidable challenger in the form of Ron DeSantis. According to the RealClearPolitics betting averages, he is the odds on favorite to win back the presidency." 

"And unless prices begin to go down, which they likely won't, and the border somehow improves, which it won't, and these wars overseas suddenly end, which they won't, it's hard to see how Biden turns us around as he continues to get older and less visible to American voters," Concha added. 

Regarding the survey, Bruce argued that Biden's "remarkably low poll ratings are even more shocking because he has had the general support of the legacy media." 

"The Democrats don't seem to realize that their success in 2020 using the basement strategy has given them the entirely wrong impression about the American people," she said. "They believe they can do it again, but what they had in 2020 that they don't have now is the trust of the American people."

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The poll found that just 31% of Americans approve of how Biden is handling the economy, while 56% disapprove. And Biden's rating on immigration and the border crisis is especially low, according to the ABC-produced poll, which found just 18% approve of the job he's done, while 63% now disapprove.

Biden is polling at 28% approval among Independents, while the survey found he's 21 points below average among African Americans and 15 points below average among Hispanics.

"Biden’s numbers are nothing short of disastrous at this stage," Fox News contributor Guy Benson said. "With an approval rating of 33%, and underwater by 25 points on the economy, he’s going to have to run an extremely negative campaign to try to compensate for this historic weakness. There’s a reason why Brit Hume recently said on my radio program that Biden is the weakest presidential incumbent he’s seen in his decades of political coverage." 

Trump was in New York on Tuesday as jury selection kicked off in the defamation trial stemming from columnist E. Jean Carroll's claims that he sexually abused her in the 1990s. The former president was then expected to head to New Hampshire, where he'll be joined at a rally by former rival Vivek Ramaswamy. 

Ramaswamy suspended his 2024 presidential campaign and endorsed Trump after coming in fourth place in Iowa. New Hampshire's primaries are next week.