In the 1920s, Calvin Coolidge, the US president at the time, called the country's democracy the "greatest hope of humanity". But a century later, the 2020 presidential election is hardly a shining example of representative government.
President Donald Trump has given warnings about widespread postal voting fraud and claimed the election on November 3 could be rigged.
Campaigners describe millions of Americans being blocked from balloting by needlessly strict and discriminatory voter registration rules.
According to Pew Research Centre, only 55.7 per cent of Americans voted in the 2016 election, putting the US towards the bottom of the turnout list of rich countries.
The list is led by Belgium, where 87.2 per cent of the population voted in 2014.
In a survey of the perceived integrity of elections from the University of Sydney, the US ranks 57th globally and is among the lowest-scoring rich countries, alongside such relative newcomers to democracy as Kosovo and Romania.
Many US pro-democracy campaigners accuse Mr Trump's Republican Party of deliberately suppressing the votes of Latinos, black people and other left-leaning minorities in a bid to retain power as demographics shift in the US.
The National assesses how turnout is being affected this year.
Reformed, but not for voting:
More than five million Americans are unable to vote because they were convicted of a crime, according to the Sentencing Project. That number is falling across the US, but more than 8 per cent of adults in Alabama, Mississippi and Tennessee remain disenfranchised for this reason.
In 2018, Florida residents voted in a referendum to allow felons to vote. While 67,000 have registered, more than 900,000 of the state's convicts who have completed their sentences remain unable to cast ballots, often because of unpaid court-ordered fines.
The battle rages on with Mr Trump accusing billionaire Mike Bloomberg of being a criminal for helping to raise $16 million to pay off outstanding fees that prevented former felons from casting a ballot.
Proving who you are:
A worrying 11 per cent of Americans cannot register to vote because they lack the required government-issued identity card, according to the Centre for American Progress, a liberal think tank. Ten states have strict voter ID laws, a report by the centre says.
Nationally, turnout is suppressed by as much as 3 per cent. Minorities and students are less likely to meet registration rules than others.
In Georgia, about 53,000 registered voters received a "pending" status on their files in 2018 because of minor misspellings or missing hyphens on registration documents, the report says. Seventy per cent of them were black.
Long journeys and long lines:
Officials across the US closed hundreds of polling stations in recent years, the centre says. As a result, some voters struggle to get to a polling station and others find long lines when they arrive.
This is especially true in Latino, black and other minority neighbourhoods. Long lines deterred about 730,000 Americans from voting in 2012, according to a study in 2016.
Georgia closed hundreds of polling stations in recent years and when early voting began in October people reported 10-hour queues and more.
This campaign season, Texas Governor Greg Abbott, a Republican, tried to limit each Texan county to having only one drop-off point for absentee ballots. He was blocked by a judge.
Intimidation:
Mr Trump sparked controversy during the first presidential debate when he urged the neo-fascist Proud Boys to “stand back and stand by” before the election on November 3.
Critics say Mr Trump was using the famously truculent group to intimidate minority and left-wing voters.
There is a long history of racially charged intimidation in US elections. During the 2018 mid-term elections white supremacist groups unleashing barrages of racist robocalls to voters' homes.
In Miami, a police officer wearing pro-Trump face mask at a polling station drew criticism and there have been protests by Trump supporters trying to block early voting.
Still, intimidation may not be working. Record numbers of Americans have turned out for early voting in some states already this year.
The purged:
Many US voters have turned up at polling stations on election day only to discover their name has been purged from the voter roll and they cannot cast a ballot.
So-called voter roll purges occur with ever-greater frequency, says the Brennan Centre for Justice, a voting watchdog. Between 2014 and 2016, states removed about 16 million voters from rolls. Officials say they are "cleaning up" lists and tackling voter fraud, but critics say it is often a deliberate ploy to suppress turnout.
Gerrymandering:
American politicians have mastered the dark art of shifting electoral boundaries to influence the outcome of a vote.
Boundaries can be configured so as to pack as many like-minded voters as possible into a small number of districts and distributing the rest in other districts too sparsely to form a majority. It skews results.
In Pennsylvania in 2012, Democratic candidates received about 50 per cent of votes in House of Representatives races, but Republicans took 75 per cent of the congressional seats.
The list goes on ...
There are many other ways that voters run into problems. In the past, party activists have phoned registered voters on election day, urging them to go out and cast a ballot, only to mistakenly direct them to the wrong polling stations.
Broken and malfunctioning voting machines have also been a bugbear, with hardware succumbing to problems such as humidity and freezing temperatures.
For a nation that proudly brands itself the world’s oldest continuous democracy, the creaking system has many stumbling blocks – intentional or otherwise – to speedy, efficient vote casting.
