Donald Trump walks to address the media before boarding Marine One

Democrats in the House Judiciary Committee have launched the first impeachment hearings into allegations that Donald Trump obstructed justice and abused power, with the president's former campaign manager Corey Lewandowski appearing before the committee as the first witness to testify on questions that were raised by the Mueller report released earlier this year.

The witness had been gagged by the White House, however, and two more aides – Rick Dearborn and Rob Porter – were reportedly told to ignore subpoenas and not attend the session with the Democratic-led panel on the grounds that they are protected by “absolute immunity”.

"The White House has no authority legal or otherwise to give these orders," House Judiciary chairman Jerry Nadler said of those gags.

But, Mr Lewandowski nevertheless refused to answer questions from Democrats, citing a gag letter from the White House, where he never worked.

The president’s latest campaign rally on Monday evening saw him attempt to appeal to the Hispanic voters of New Mexico he alienated in 2016, a day bookended by his calls for resignations at The New York Times over the latest sexual misconduct allegations against Supreme Court justice Brett Kavanaugh and a new poll forecasting Mr Trump’s defeat in key 2020 swing states.

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