If not Joe Biden, then who?

Thursday’s presidential debate was an unmitigated disaster for President Biden, Democrats and indeed the world. To be sure, Biden’s performance confirmed what Democrats feared most, yet many voters already knew: Biden is too old to serve as commander in chief.

To that end, the debate made it abundantly clear that Democrats cannot beat Donald Trump — or the extremism he represents — with Joe Biden leading the ticket.

With that in mind, Democrats should seriously consider replacing Biden before their convention in August, giving the party the opportunity to put forward a stronger candidate who is capable of taking on Trump.

But to trigger an open convention, party leaders like former Presidents Bill Clinton and Barack Obama, in concert with congressional leaders Chuck Schumer, Nancy Pelosi and Hakeem Jeffries, must plead with Biden to step aside. If amenable, the president would release his delegates, triggering the first open Democratic convention in the modern political era.

Such a convention, the likes of which have not been seen since 1984, would generate great interest, media attention and excitement among a formidable bloc of voters who are unsatisfied with both Trump and Biden.

Indeed, voters are desperate for a younger, more inspiring Democratic candidate who can lead us into the future. To be sure, the latest New York Times-Siena poll reports that 61 percent of likely voters and 41 percent of Democrats believe their party should nominate someone other than Biden. But who?

In truth, the first, and now most likely, candidate to replace Joe Biden is Vice President Kamala Harris. Harris is the most obvious choice given her experience in the administration, her leading role on the campaign and the simple fact that her name is already on the ballot.

While polling on the matchup is limited, surveys that ask voters to decide between Harris and Trump do not paint a rosy picture for the left. Real Clear Politics’s polling average shows Harris losing to Trump by 6 points, 49 percent to 43 percent, whereas Biden only loses to Trump by an average of two points (47 percent to 45 percent) as of this writing. In that same vein, Harris’s favorability rating is worse than Biden’s, sitting at a dismal 39 percent.

With that in mind, the major question of a last-minute Harris candidacy is whether or not the campaign could improve her viability enough over the next five months to defeat Trump. If it cannot be done, Democrats must consider another, more viable, option such as California Governor Gavin Newsom.

In fact, Newsom’s candidacy has been looming in the background of Democratic politics for years. However, it wasn’t until the aftermath of Hamas's attack on Israel on Oct. 7 — when Democratic factions organized en masse to vote against President Biden in the primaries — that Newsom came out of the shadows.

Newsom has obvious obstacles to overcome — most notably public statements he has made to Florida Governor Ron DeSantis that he would not be the Democratic nominee in 2024. Moreover, the Biden campaign deployed Newsom as its top surrogate in the post-debate spin room on Thursday night, where Newsom remarked that he would “never turn [his] back” on the president because of one poor performance.

However, Biden’s stepping aside for anyone other than Harris would be the biggest hurdle for Newsom to overcome. Indeed, Harris’s candidacy would be historic, and the obvious blowback from replacing the first female person of color to serve as vice president on the ticket could do irreparable damage to the Democrats’ already crumbling coalition.

One possible solution that’s been floated is that Newsom and Harris could swap roles. Whereas Newsom steps in for Biden and can choose his own vice president, Harris could serve out the rest of Newsom’s term as governor of California and run for the office in 2026.

Even so, the limited polling that exists on the matchup is not favorable for Democrats; Trump led Newsom by a 17-point margin in the latest March poll.

While these ideas may sound preposterous, alarm bells are blaring across the Democratic Party after Thursday’s debate. No solution is off the table.

Other popular contenders to replace Biden are former Democratic nominee Hillary Clinton, former first lady Michelle Obama, Michigan Governor Gretchen Whitmer, Pennsylvania Governor Josh Shapiro, Sen. Amy Klobuchar (D-Minn.) and even former Vice President Al Gore.

Unsurprisingly, each of these party bosses' chances to win the 2024 presidential election soared on popular betting platforms following Thursday's debate, though they all remain longshots. Hillary Clinton stands at +5,000, Michelle Obama at +1,600, Newsom at +650, Whitmer at +4,000, Shapiro is at +20,000, and Klobuchar is at +15,000.

Regardless of whom Democrats ultimately choose as their nominee, exit polling from Thursday’s debate underscores a much larger issue for Democrats. Indeed, their inability to present a coherent message on kitchen table issues — notably the economy and inflation, the southern border and foreign affairs — has been glaring.

Put another way, despite Trump’s lies and obvious lack of policy knowledge, debate viewers rated him as more equipped than Biden to handle the economy (+25), immigration (+28) and foreign policy (+12). And, given the lack of coherence in most of Biden’s answers, it is unsurprising that debate viewers graded Trump as having a better plan to solve the country’s problems by 15 points, 42 percent to 27 percent.

And, despite Trump throwing below the belt insults at Biden, it is fair to say that Trump succeeded in not appearing too volatile. To be sure, Trump’s favorability dropped by only 1 point following the debate, and now sits at 41 percent, per CNN. 

How this will ultimately affect the distribution of votes remains to be seen, but exit polling data show that there could be significant movement on the margins. In fact, 14 percent of debate viewers now say they are reconsidering whom they will vote for, while 5 percent say they changed their mind. And, most notably, post-debate viewers broke for Trump by 8 points, 48 percent to 40 percent, while 11 percent of debate viewers say they will vote third party, and 2 percent remain undecided.

To be frank, we both voted for Joe Biden in 2020. And while we’ve been bearish on his chances of winning this November, this has not undermined our hope for his administration to be successful.

However, last week's debate proved that keeping Joe Biden as the party’s nominee is not only irresponsible, but selfish, if we cannot find another candidate to lead the Democratic ticket in 2024.

Douglas E. Schoen and Carly Cooperman are pollsters and partners with the public opinion company Schoen Cooperman Research based in New York. They are co-authors of the book, “America: Unite or Die.”