The United States Supreme Court is set to be conservative for decades following the elevation of controversial Judge Brett Kavanaugh to the high court on Saturday.

The judge - who had been accused of a drunken sexual assault - was confirmed in a narrow 50-48 vote in the Senate, allowing US President Donald Trump to deliver on a longstanding conservative dream.

The vote triggered protests on the steps of the Supreme Court in a sign of deep divisions across the US, just weeks before mid-term elections on Nov 6 that will be a key test for Mr Trump's presidency.

The bitter battle over the judge could also erode faith in the Supreme Court itself, pundits say.

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