WASHINGTON, United States (AFP) – Conventional wisdom says a Donald Trump nomination should bring presidential election gold for Democrat Hillary Clinton – but given how the brash billionaire has outperformed expectations at every turn, it might not be so simple.

Analysts and experts who spoke with AFP acknowledged that Trump’s strong performance on Super Tuesday, when millions of Democrats and Republican voters in a dozen states chose their nominee, put him in the driver’s seat on the road to the GOP nominating convention in July.

From there, it would be a head-to-head battle against the Democratic nominee, most likely Clinton, who dominated rival Bernie Sanders in seven of the 11 states where party voters had their say Tuesday.

At first glance, the experience and temperament of a former secretary of state, senator and first lady would be enough to see her soar against a politically untested, deeply controversial billionaire who has yet to flesh out many of his policies.

“It certainly would be a good thing” for Democrats, Norman Ornstein of the American Enterprise Institute said about a Trump nomination.

A recent CNN poll showed Clinton beating Trump 52 per cent to 44 per cent among registered voters in a hypothetical matchup. Other polls have reflected similar results for months.

But a November Clinton victory is “no sure thing,” Ornstein cautioned.

“Big divisions in the Republican Party are good for Democrats, but that doesn’t mean if Donald Trump is the nominee that there is certainty that he’ll lose.”

Trump has rallied supporters with his politically incorrect talk about immigrants and trade.

But he has ruptured the party with his hostility: he has called some Mexicans rapists, urged a ban on Muslims entering the United States, mocked women and the disabled, prompting outcries from establishment Republicans.

Many experts have assumed that Trump’s insults, exaggerations and taunts will hurt him in November.

But the 69-year-old real estate mogul appears to operate in an alternate reality, unrestrained by traditional political rules.

“Trump has broad appeal,” Republican strategist Brad Marston of Massachusetts said.

“Yes, he has incredibly high negatives, but both on the left and right, people are tired of their leaders lying to them.”

Clinton meanwhile is the ultimate establishment candidate, who polls poorly with voters on honesty and trustworthiness.