Donald Trump’s former campaign manager Corey Lewandowski has refused to answer most questions at Democrats’ first hearing in what they are calling an impeachment investigation.

Mr Lewandowski was following White House orders not to discuss confidential conversations with the US president beyond what was already public in former special counsel Robert Mueller’s report.

Corey Lewandowski
Corey Lewandowski was Donald Trump’s former campaign manager (AP/Jacquelyn Martin)

As the hearing began, Mr Lewandowski – a devoted friend and supporter of the Republican president – demanded that Democrats provide him a copy of the report, sending Democratic staff scrambling to find one.

Mr Lewandowski then just read directly from report, making it clear that he wouldn’t say much beyond what Mr Mueller wrote. Republicans on the panel then forced a series of procedural votes, immediately sending the hearing into disarray.

House Judiciary Committee chairman Jerrold Nadler accused Mr Lewandowski of filibustering.

House Judiciary Committee chairman Jerrold Nadler
House Judiciary Committee chairman Jerrold Nadler (AP/J Scott Applewhite)

The hearing is the latest in a series of hurdles the committee has faced as it tries to investigate Mr Trump.

Mr Mueller himself gave evidence this summer, with no bombshells. Two other witnesses who were subpoenaed alongside Mr Lewandowski – former White House aides Rick Dearborn and Rob Porter – will not show up at all, on orders from the White House.

It also underscores what has been a central dilemma for House Democrats all year — they have promised to investigate Mr Trump aggressively and many of their base supporters want them to move quickly to try to remove him from office. But the White House has blocked their oversight requests at every turn, declining to provide new documents or allow former aides to give evidence.

The Republican Senate is certain to rebuff any House efforts to bring charges against the president. And moderate Democrats in their own caucus have expressed nervousness that the impeachment push could crowd out their other accomplishments.

Still, the judiciary panel is moving ahead, approving rules for impeachment hearings last week. Among those guidelines is allowing staff to question witnesses, as will happen for the first time with Mr Lewandowski.

Mr Lewandowski was a central figure in Mr Mueller’s report. Mr Mueller’s investigators detailed two episodes in which Mr Trump asked Mr Lewandowski to direct then-attorney general Jeff Sessions to limit Mr Mueller’s investigation. Mr Trump said that if Mr Sessions would not meet with Mr Lewandowski, then Mr Lewandowski should tell Mr Sessions he was fired.

Mr Lewandowski never delivered the message but asked Mr Dearborn, a former aide to Mr Sessions, to do it. Mr Dearborn said he was uncomfortable with the request and declined to deliver it, according to the report.

Mr Porter, a former staff secretary in the White House, took frequent notes during his time there that were detailed throughout the report. He resigned last year after public allegations of domestic violence by his two ex-wives.