What would actually happen if Donald Trump was impeached?

Calls for his impeachment have dogged the 45th President since he took up his seat in the Oval Office. But what would actually happen if Trump was impeached?

The 45th President's time in office has already been one of the most controversial in history. Donald Trump has been accused of colluding with Russia to rig the outcome of the US election, threatened nuclear war with North Korea and shown leniency towards white supremacists in Charlottesville. But will Donald Trump be impeached?

Since the arrest of Trump's former campaign manager Paul Manafort and lawyer Michael Cohen, many believe it is now a question of when, not if, the President is impeached.

'I think [Trump] has to realise that the countdown to impeachment has already started' Democratic Congressman Al Green told the media. 'He, at some point, will have to choose if he will face impeachment or if he will resign. It will be his choice. The congress will have no choice but to act.'

Trump has, as ever, come out fighting. 'I don't know how you can impeach somebody who has done a great job,' Trump told Fox News, addressing the question of an impeachment for the first time. 'I will tell you what, if I ever got impeached, I think the market would crash. I think everybody would be very poor because, without this thinking, you would see – you would see numbers that you wouldn't believe, in reverse.'

But what exactly is an impeachment, how does the impeachment process work and what would happen if Trump was impeached?

What is an impeachment?

An impeachment is defined in the US constitution as when 'the president or another government official is brought up on charges and tried by the Congress, and if convicted, is removed from office.'

What does it take for a President to be impeached?

Something pretty serious. According to the US constitution, a President must commit 'treason, bribery, or other high crimes and misdemeanors' to be impeached. Two Presidents have been impeached before: Andrew Johnson for illegally removing his secretary of war from office in 1968 and (more recently) Bill Clinton for lying under oath to a federal grand jury about his relationship with Monica Lewinsky in 1998. One of the biggest scandals to ever hit the Presidency was Watergate in 1972, when President Nixon attempted to cover up a break-in at the Democratic National Committee headquarters, where key documents were stolen and phones bugged. Nixon resigned before he was formally impeached. If it can be proved that Trump colluded with Russia - a hostile foreign power - to secure his election victory, he will have committed a highly serious, treasonable offence, arguably one far worse than Watergate.

How likely is it that the President will be impeached?

In May this year lawyer and former Director of the FBI Robert Mueller was appointed by the Justice Department to investigate the Trump team's possible collusion with Russia. This month Mueller appeared to ramp his investigation up a gear by appointing a grand jury to investigate the allegations. The purpose of a grand jury is to establish whether a case should go to trial, it also has the right to issue subpoenas, meaning that key names involved in the Russian collusion scandal must testify under oath. Mueller's appointment of a grand jury still doesn't mean Trump will be impeached. According to Politico most grand jury investigations do result in an indictment of some kind, but this could be against a lower-level member of Trump's team rather than the President himself.

What stands in the way of Trump's impeachment?

Only the House can initiate charges and an impeachment requires a two-thirds majority vote in the House of Representatives and a two-thirds majority in the Senate. However, the House and the Senate are currently still under Republican control, so only a rebellion from Trump's own party would make it happen. The Senate would then begin a trial against the President, ending with a vote. A two-thirds majority vote against the President would be enough to remove him from office.

Is the President likely to resign before impeachment?

Jackie Speier - who sits on the House Permanent Select Committee on Intelligence - has said she believes, given the mounting evidence on the Trump team's ties to Russia, that the President is likely to resign before impeachment. 'I have always thought that he was never going to fulfil his full term' she said, 'I am more convinced that he will leave before any impeachment would take place.'

How do Americans feel about an impeachment?

According to a poll taken late last year by the Monmouth University Polling Institute, 41% of American voters would like to see impeachment proceedings against President Trump, making him one of the most unpopular Presidents in history. A Gallup poll showed the President's approval ratings at an all-time low, having dipped to just 34%.

Who takes over if the President is impeached?

If Trump is forced to resign in the next four years then Vice President Mike Pence will take his place in the Oval Office. In contrast to Trump's maverick behaviour and posturing as a Washington outsider, Pence has strong party links and is regarded by many Republicans as a safe pair of hands. Though as a right-wing conservative with strong views on issues such as abortion, Pence is considered by some to be as quietly dangerous as his more volatile boss.