Former Vice-President Joe Biden continues to leave open the possibility of running for president. According to a report Saturday by the Associated Press, Biden told foreign policy aides in a private meeting that he was still weighing a run for president in 2020 but had not come to a decision.

Political pundits have been intrigued by the idea of Biden running for president. Having served as vice-president for eight years alongside Barack Obama, he brings instant name recognition. Biden also has a wealth of experience, having served in the Senate from 1973 to 2009.

"A couple weeks ago (Biden) was in Reston, Virginia, campaigning for [then-Virginia gubernatorial candidate] Ralph Northam. So he's a winner," former Democratic strategist and CNN commentator Paul Begala said in a panel session after Northam won the election in November.

Sen. Ben Sasse, a Republican from Nebraska, said in April that Biden would have easily won the 2016 election. “If Joe Biden would have run against Donald Trump, Biden would have won in a landslide,” Sasse told Ana Marie Cox of the New York Times Magazine.

The 2020 field remains hazy with less than nine months before the 2018 midterm elections. Should Biden throw his hat into the race, he would likely face strong competition from a deep Democratic field. The last time there was a Republican incumbent was 2004, prompting 10 Democrats to compete for the nomination.

Former Democratic chairman Ed Rendell praised Biden as a "superstar" in a December interview and claimed Biden would earn a convincing victory.

“There's only one person I can say who will definitely win the election and has a superstar appeal in almost every state in the union, and that's Vice-President Biden,” Rendell said on John Catsimatidis’ AM 970 radio show in New York.

“To me it’s clear-cut: Joe Biden is our superstar. If he decides to run I think he will win overwhelmingly.”

Oddsmakers are less optimistic than Rendell about Biden's chances. According to betting site Bet365, six candidates have a better shot than the former Delaware senator.

The site lists President Donald Trump as the favorite at 2/1 odds. Biden is listed at 22/1 odds, and trails Vice-President Mike Pence (10/1), along with Sens. Elizabeth Warren of Massachusetts and Kamala Harris of California — both Democrats listed at 11/1 odds. Other Democrats ahead of Biden are Sens. Bernie Sanders (12/1) of Vermont and Kirsten Gillibrand (20/1) of New York. 

But according to a CNN poll in January conducted by SSRS, Trump would be the underdog against  Democrats, including Biden. In a hypothetical matchup, Biden would have a big edge on Trump: 57 percent to 40 percent amongst registered voters. Trump also trails against Sanders, 55 percent to 42 percent. 

Biden's flirtations with a White House run are nothing new. He mounted a failed attempt to capture the Democratic nomination in 1988 and in 2015 openly addressed the prospect of entering the Democratic primaries despite favorite Hillary Clinton and top-challenger Sanders immersed in what was then a tight battle.

Age may play a factor in the primaries and the general election. Biden will be 78 years old on Nov. 3, 2020, but he's also only three years younger than Trump, who became the oldest elected president in U.S. history. Only Sanders, who will be 79 years old in November 2020, would be older than Biden in the possible field. Clinton, who won the popular vote by 2.9 million votes, would be 73 years old on Election Day if she chooses to run. 

In an interview this month with NBC's Andrea Mitchell, Biden was asked about whether he might "overshadow" younger candidates like Sen. Cory Booker of New Jersey, Harris and Gillibrand, who may have a strong chance to win the Democratic nomination. Biden pivoted from the question, stating that his top priority is electing Democrats to Congress.

Trump, meanwhile, appears to be the most vulnerable first-term president in recent memory. The most recent Gallup poll showed Trump with just a 40 percent approval rating and a 57 percent disapproval rating. Also weakening Trump's chances is the fact that Republicans have failed to win the popular vote in six of the last seven presidential elections. Trump may have to once again carry states like Michigan, Pennsylvania and Wisconsin to have a legitimate chance to stay in office. 

But the last time an incumbent lost a presidential election was 1992, when George H.W. Bush was defeated in a three-way race by Bill Clinton. Independent candidate Ross Perot received 19 percent of the vote. 

GettyImages-632182850 Joe Biden and Dr. Jill Biden leave the White House on the day Donald Trump was sworn in as president. Photo: Getty