Joe Biden faces a key test of public standing in a tight and closely watched campaign for governor in Virginia next month. So important has the fight now become in being seen as a bellwether for the 2022 midterm elections, that two ex-presidents are weighing in on the battle.

For Biden and the Democrats winning Virginia would hold out the prospect of keeping a grip on congress next year and avoiding being seen as a lame duck administration. For Republicans, a win could pre-sage a major comeback in 2022 and a return to electoral strength of a party still dominated by Donald Trump.

The stakes are so high that both Trump and Barack Obama are intervening in the race.

Last week, Trump called in to a gathering of Virginia supporters, urging them to vote for the Republican candidate Glenn Youngkin, and calling him “a great gentleman”. Meanwhile, Obama will later this month arrive in the state to boost turnout among Black voters. “The stakes could not be greater,” Democratic candidate Terry McAuliffe said, as he announced Obama’s campaign support on MSNBC last week.

The proxies in the contest, McAuliffe, a former governor running for the job he held from 2014-18, and first-time Republican challenger Youngkin, are currently polling relatively closely at 48.5% and 46.4%, according FiveThirtyEight – making the race unpredictable and tight.

The men are running to replace the state’s Democratic governor Ralph Northam who has been in the party’s political doghouse since 2019 when it was revealed his 1984 medical school yearbook page contained a photo of one person dressed as a member of the KKK and another in blackface impersonating an African American.

The Virginia race comes against a backdrop of bad news for Biden, who has seen his popularity fall in the aftermath of the botched Afghanistan withdrawal and legislative gridlock on the main plans of his domestic agenda and growing uncertainty of post-pandemic economic recovery. His approval rating has sunk from 55% in March to about 44% now.

But so, too, does the contest present a test for Trump, who lost Virginia by 10% in 2020, but is increasingly seen to be gauging his hold on the Republican party and its voters ahead of the midterms, which could then swing his decision to run for re-election in 2024.

Nor is Trump’s intervention in the race a win-win for Youngkin. The two men are not likely to campaign in person as Youngkin must simultaneously appeal to pro-Trump rural voters, but not telegraph any association so blatantly that he turns off moderate Republican voters in Virginia’s Washington-centric northern suburbs where elections in the state are often decided.

Bob Holsworth, a longtime political analyst in the state, told the Washington Post that if Trump were to hold a rally in the state, it would be a “disaster” for Youngkin. “The more he shows up and he more he participates, the worse off it is for Youngkin,” he added.

But Trump countered that political wisdom with some of his own: “The only guys that win are the guys that embrace the Maga movement,” Trump said in an interview with conservative talkshow host John Fredericks.

Instead of overtly embracing Trump, Youngkin has campaigned with Texas senator Ted Cruz and with former South Carolina governor Nikki Haley. But he steered clear of an event hosted by Trump strategist Steve Bannon who may face contempt charges on Tuesday for refusing to cooperate with an investigation into the 6 January Capitol riot. Youngkin was also careful to criticize the Bannon event’s use of a flag that had reportedly been flown at the 6 January insurrection.

Youngkin’s hands-off, hands-on approach is also designed to not raise the hackles of relatively unengaged democratic support for McAuliffe, who has his own endorsement issues to deal with.

For his part, Virginia’s former governor comes with the baggage of close ties to the Clintons, whose popularity among independents and left-wing Democrats is far from assured. Last month, Hillary Clinton, whose first, failed presidential nomination campaign was co-chaired by McAuliffe sent out a fundraising email. That was followed by a fundraising event hosted by Bill Clinton.

But other Democratic heavy-weights are traveling to Virginia to soothe Democratic anxiety and try to propel McAuliffe’s campaign toward the decisive victory they need. Georgia Democratic star Stacey Abrams and Atlanta mayor Keisha Lance Bottoms and first lady Jill Biden are also expected in the state’s northern suburbs, while House speaker Nancy Pelosi plans a fundraiser.

But Biden himself has and will likely remain absent from Virginia. Mirroring Youngkin’s relationship to Trump, McAuliffe and his aides have expressed fears over associating with Biden. McAuliffe recently described the president as “unpopular” in Virginia.

McAuliffe has also indicated that legislative impasse in Washington is damaging to Democrats in the country at large. “Democrats have got to quit talking, and they’ve got to get something done,” McAuliffe told The Washington Post. “You got elected to get things done. We have the House, Senate and White House.”

Hanging over Democratic heads are the memories of losing the midterm elections in 2010, a crushing defeat for Obama that was predicted when Democrats lost a Senate seat in Massachusetts while trying to push through a controversial healthcare reform bill.