The 2016 US Presidential race is shaping as the wackiest on record, with the two frontrunners – Donald Trump and Hillary Clinton – each having to cover up or fend off details about past transgressions to get elected.

It is a battle between a dodgy real estate developer and a former Secretary of State who fell into a habit of sending thousands of classified emails from an unsecured home computer.

Alternatively, the political dogfight might be better billed as a former bankrupt pokies operator versus the pollie who got paid millions to speak at functions staged by fat cat bankers on Wall Street.

• Hillary Clinton wins South Carolina primary
• Trump wins Nevada Republican caucuses
• Why a Trump victory is exactly what IS wants

It all sounds like a crazy storyline drummed up by a gonzo journalist, but right now Democrats and Republicans don’t seem too bothered that the campaigns of their leading contenders could buckle in a flash.

In Mrs Clinton’s case, there is the spooky risk that law enforcement authorities could lay charges against her any time before the November poll for president.

The Federal Bureau of Investigation has more than 100 officers poring over evidence of her work-from-home tendencies to assess whether she breached national security laws.

Hillary Clinton has been slammed for her secure email server. Photo: AAP

Mr Trump’s position is even more bizarre because he has a track record of offending African-American and Hispanic minorities.

The Justice Department sued one of his companies in 1973 alleging it had engaged in racial discrimination.

The long-running case was eventually settled out of court.

If elected, he promises to slap a ban on all Muslims entering the country.

He has also threatened to erect a big wall along the southern border of the United States to keep out Mexicans.

He hit a new low on Sunday when he refused to disavow himself from Ku Klux Klan grand wizard David Duke.

Mr Duke backed Mr Trump’s previous run for the presidency in 2000.

Bernie and Marco could still steal the show

Mr Trump is unelectable for the Republican party in the big states where presidential contests are decided, such as Florida and Ohio.

There is also his refusal to disclose his tax returns.

These days, most presidential candidates don’t need to be prodded about how much tax they pay, they just accept that such disclosure is part of the political terrain they work in.

Except for Mr Trump.

Young voters in the US have warmly embraced Bernie Sanders. Photo: AAP

Both Mr Trump and Mrs Clinton are expected to carry most of the 13 state primaries to be held on Wednesday (AEDT), but it won’t necessarily spell the death-knell for the flagging campaigns of Democrat candidate Bernie Sanders and those of Republican hopefuls, Marco Rubio and Ted Cruz.

In fact, Mr Cruz looks set to gain some momentum by edging out Mr Trump in the vital Texas primary.

Mr Rubio will struggle in most states but is banking on a win in the Florida primary in a few weeks to capitalise on a likely Trump implosion.

According to data collated by the Centre for Responsive Politics (CRP), both Mr Rubio and Mr Cruz have plenty of cash to help them stay in the race for at least another month.

As at the end of February, Mr Cruz was reported to be sitting on $25.5 million of cash, while Mr Rubio had around $6 million left to spend.

Bernie Sanders will try to stay in the Democrat race in the hope that Mrs Clinton is made unelectable by the FBI, but he will be financially stretched.

The CRP reported that Mr Sanders ran out of cash last week and now owes suppliers at least $100,000.

The Sanders campaign has already spent $81 million, while Mrs Clinton has splurged $110 million. She still has $44 million in the bank.

This presidential contest looks so crazy that Americans might even countenance electing an independent to sit in the White House.

A smokey like New York billionaire Mike Bloomberg might even claim the prize just as Steven Bradbury did on the ice in Salt Lake City 14 years ago.