The Democratic contender in November's United States presidential election appears to have the easy job.
Former Vice-President Joe Biden is the clear front-runner in polling and has managed to make himself a hard-to-strike target as the incumbent struggles with a pandemic and millions unemployed.
But sitting US Presidents rarely lose bids for re-election in a two-candidate race. Bill Clinton benefited from Ross Perot's run in 1992 to down President George Bush snr.
President Donald Trump also has a big war chest for anti-Biden campaign ads.
Here are four challenges Biden faces.
1) A vote for or against?
Throughout the primary season Democrats and others opposed to Trump sought the most electable candidate.
Biden was able to leverage his name recognition and experience to become the figure most party voters in the end could hang their hat on. But other candidates had more motivated and enthusiastic supporters.
Biden's coalition has widened in the general campaign to include a majority of independents and some disgruntled Republicans.
It looks a lot like the voter battalion that took back the House of Representatives for the Democrats in 2018. Polls confirm that suburban voters - who were a key blue bloc in the Midterms but normally favour Republicans – are still with the Democrats in 2020.
Trump has been unable so far to find a way to damage and define Biden, a classically shapeshifting centrist who has managed to widen his policy umbrella to include more progressive policies while maintaining his moderate persona.
BREAKING: Joe Biden opens up a 15-point lead over Pres. Trump in a new @ABC News/Washington Post poll, ahead 55-40% among registered voters. That advantage narrows to 54-44% among likely voters. https://t.co/wo5UBbbf8g— ABC News (@ABC) July 19, 2020
Personal enthusiasm for Biden has been weak in polling all year. But this election is a referendum on a very divisive President against the background of upheaval in the lives of voters.
An ABC/Washington Post poll showed that 94 per cent of Trump voters were keen to back him compared with 79 per cent of Biden voters for their candidate. But polls also show that Democrats have a higher level of interest in the election than Republicans.
Ultimately it doesn't matter whether a voter is more motivated to dump a leader than vote one in.
But should the election tighten, a percentage of Biden's support could turn out to be soft and the lower level of excitement in the Democratic base for their candidate could matter more. Trump needs to get within about 4 per cent of Biden to be competitive and possibly pull off an Electoral College win.
Biden's coronavirus, jobs, and climate change policies could help build enthusiasm.
A look across the latest polling has Biden winning in the suburbs by north of 15 points on average. No Dem in the modern era has won the suburbs by double-digits, save maybe Johnson in 64. It would be a historic win. https://t.co/gCCzWciqdD— (((Harry Enten))) (@ForecasterEnten) July 19, 2020
2) Trump's closing opportunity
The pandemic crisis rewards traditional political approaches and competence. Plenty of world leaders have seen their popularity rise based on how they have handled Covid-19.
That is not happening with Trump. Polls show majority disapproval for how the President has handled the coronavirus. Biden leads on the issue by 51 per cent to 34 per cent in a new Fox poll. Three polls last week showed Trump's rating on the issue declining from 42 per cent, 43 per cent and 45 per cent last month to 35 per cent, 37 per cent and 38 per cent.
Throughout the 2016 election campaign and his presidential term, Trump has been unable to shift from his basic approach of divide and rule and keeping his base on the boil. Yet the political realities on the ground, and the electorate itself, have shifted.
The opportunity is still there for Trump, as the incumbent, to put the weight of the Federal Government behind efforts to suppress the virus, and shield people from its health and economic impacts.
Can Trump change? It seems highly unlikely. At this stage the window is open - though slowly closing. The President's opponent is only able to present a character and policy contrast and a promise of change.
Trump's advantage over Biden on who is considered best to handle the economy has largely eroded – from an eight-point lead in March in the ABC/Washington Post poll to a two-point lead now. Biden is trying to get ahead on that issue with his economic policy rollouts.
'In the NBC/WSJ survey, 80 percent of Democrats rated their level of interest in the election as a “9” or “10” on a 1-10 scale, more than the 74 percent of Republicans who gave the same ratings.' https://t.co/2NA98FlINY via @politico— Shibley Telhami (@ShibleyTelhami) July 19, 2020
3) Biden's age and big decision
Trump is the oldest President ever elected, being 70 at inauguration in January 2017. Biden will be 78 in late November.
Trump has tried to create doubt about Biden's capacity to be President, but his own frequently rambling statements have raised questions of their own and blunted the impact of his attacks. The Fox poll put Biden ahead on "mental soundness".
The former Vice-President is famous for his gaffes, but coronavirus restrictions have limited Biden's appearances and potential for mishaps.
However, Biden's age complicates things for the Democrats. It means he may only serve one term which would cause 2024 to be an open contest rather than a potential re-election.
His pick for running mate needs to be obviously qualified for the job and a believable potential President. It is a chance to create some excitement for the ticket but the bottom-line is to not blow it with an unconvincing choice.
TRUMP: "I think mail-in voting is going to rig the election."— Aaron Rupar (@atrupar) July 19, 2020
WALLACE: "Are you suggesting that you might not accept the results?"
TRUMP: "I have to see."
WALLACE: "Can you give a direct answer that you will accept the election?
TRUMP: "I have to see." pic.twitter.com/mPDPLY9vsr
4) October and November surprises
Hillary Clinton's emails dogged her throughout the 2016 campaign but were especially a last-minute drag on her prospects in the final month before the election. Biden should be prepared for anything, including further incidents of hacking.
With the pandemic and economy still likely to be in bad shape by October, Trump could become increasingly desperate.
His go-to solutions to stave-off defeat could involve his law-and-order theme and appeals to nationalism.
Federal forces have been targeting protesters in Portland in recent days, and those actions could be widened to other cities. Overseas, Iran has been hit by a dozen incidents this month involving explosions and fires to industrial plants and the Natanz nuclear facility. So far Iran has avoided directly blaming the US or Israel.
What about election day and what would the US President do should he narrowly lose?
Trump has regularly claimed that voting by mail is unreliable and open to fraud. Voting early and by mail is likely to be a popular choice this year because of the pandemic.
If the availability of mail voting is cut back, then a willingness to turn out in person to vote in a pandemic becomes key and takes the election into uncharted waters.
When asked on Monday whether he will accept the election Trump replied: "I have to see ... No, I'm not going to just say yes. I'm not going to say no."
Read: Five challenges for Trump.