TO go or not to go, that is the question that must be haunting Joe Biden right now. Not that the incumbent US president has so far shown any signs of throwing in the towel on his re-election bid.

Ever since that car crash of a presidential debate in Atlanta on June 27 against Republican rival Donald Trump, Biden’s candidacy has been called into question. So far though, his campaign team have pulled out all the stops to ensure his continued run, even if you can’t help feeling that it might all come soon to a staggering halt.

Having already captured the Democratic Party’s nomination, Biden would certainly need some convincing that his candidacy is untenable and a potential disaster for the Democrats in the November 5 election.

READ MORE: Scottish party leaders make final pitches to voters as General Election polls open

That convincing, though, has yet to happen as a code of silence appears to have been the order of the day among senior Democrats reluctant to say publicly what many are doubtless talking about privately.

Even Barack Obama, no slouch when it comes to facing up to political realities, has so far rallied round Biden and released a public statement of support saying: “Bad debate nights happen. Trust me, I know.”

But time is marching on in this presidential race and if Democrats concerned over Biden’s fitness are to speak out and suggest another candidate instead of him, that time has to be now. It will not make their decision any easier that a new Reuters/Ipsos poll released yesterday showed that Biden had pulled even with challenger Trump, with both on 40% support among registered voters according to the two-day poll.

This though came in the wake of another poll by the same pollsters showing that one in three Democrats said Biden should end his re-election campaign after the calamitous debate with Trump in Atlanta.

All this is a stark reminder of just how close this contest is, despite the interminable legal and other travails that have beset the Trump campaign that should have helped throw Biden into a commanding lead.

It’s hard to overstate how much is at stake for America in the forthcoming election. In fact let me expand on that and say how much is at stake for the world, should Trump find himself back in the White House.

For his part Biden is doing all he can to convince Democrats that he is still up to the job, admitting that he “wasn’t very smart” for having travelled extensively in the weeks leading up to the debate event against Trump. But even with Biden set to talk with governors and Capitol Hill leaders this week to reassure them of his competence, the disquiet within Democrat ranks refuses to go away.

In fact if anything it has only intensified after the US Supreme Court ruling this week that Trump has broad immunity from criminal prosecution for his actions as president, a decision likely to delay his trial on charges of trying to overturn the 2020 election.

All this has only added to Democrat fears and growing momentum within their ranks that time is running out to replace Biden.

READ MORE: What kind of photo ID do I need to vote?

Just a few days ago Lloyd Doggett, a Democratic congressman from Texas, became the first politician from the president’s party to publicly call for Biden to step aside, saying “too much is at stake to risk a Trump victory” in November’s election.

“Recognising that, unlike Trump, President Biden’s first commitment has always been to our country, not himself, I am hopeful that he will make the painful and difficult decision to withdraw,” Doggett said.

His is not a lone voice, anything but. As the Financial Times reported yesterday, Jared Golden, a Democratic congressman from Maine, later published an op-ed in the Bangor Daily News, a local newspaper, saying he had no confidence in Biden’s ability to win in November.

“While I don’t plan to vote for him, Donald Trump is going to win,” Golden said.

Yet Biden’s defiance and that of his campaign team in the face of such calls for him to step down remains robust. For many of Biden’s campaign aides their decision that it wasn’t the president’s performance in Atlanta that was the problem but how the media reported it, is though beginning to wear thin with many Democrats.

It seems to have escaped their notice too that down-ballot Democrats have also been polling better than the president, particularly in the marquee Senate races.

Should these numbers begin to slip and or party donations fall then disgruntlement will only grow stronger.

Were Biden to quit his White House race then this of course also raises the question of who would replace him as the Democratic candidate.

Several names are floated as potential replacements to take on Trump with vice-president Kamala Harris leading the alternative candidates despite criticism by some that she lacks the charisma to take on the former president.

Harris at 45% currently trails Trump on 47% by two points in a CNN/SRRS poll, a smaller deficit compared to Biden’s six-point shortfall behind Trump in the same poll recently.

Jim Clyburn, one of Biden’s most ardent supporters in Congress, meanwhile appeared to contemplate change at the top, saying that while he still backed Biden as the party’s presidential candidate, he would support Harris “if he were to step aside”.

Other potential contenders include California governor Gavin Newsom on 43%, who has commonly been floated as a Biden replacement despite turning down rumours of a “shadow campaign” for the White House. He polls five points behind Trump according to the poll.

All this though remains speculation as Biden continues to tough it out and unlike in parliamentary systems, there is no real mechanism to push him aside.

Any move by him to step down of course could throw the party into turmoil and that in itself is perhaps enough to keep Democrats in line for now. But the persistent anxiety across the party about Biden’s age and fitness for office is but a fraction of that shared by many voters.

It is they who for now are expressing the most concern and who top Democrats must keep an eye on with regard to any decision that Biden must go.