Trump impeachment: Who will be making the case for and against the U.S. president in the Senate trial

As the Senate impeachment trial of U.S. President Donald Trump begins in earnest this week, those arguing for and against his removal from office are gearing up for a contentious battle.

Trump is accused of abusing his presidential power by pressuring Ukraine to investigate his Democratic rival Joe Biden, using military aid approved by Congress as leverage. Trump is also charged with obstructing Congress in the ensuing probe.

Seven House impeachment managers will make their case as to why the president should be ousted. Trump, meanwhile, will be defended by several high-profile lawyers.

Republican and Democratic senators will sit and listen to each side, acting as jurors.

The presidential impeachment trial — only the third in U.S. history — will be overseen by the chief justice of the Supreme Court, who has little actual power over the proceedings.

• Impeachment trial begins with clashes over rules and evidence

Here are the key figures whose actions will help determine whether the 45th president of the United States will be removed from office:

These seven Democratic members of the House of Representatives were chosen by Speaker Nancy Pelosi to make the case against Trump, making them de facto prosecutors:

A former federal prosecutor, Schiff is chair of the House intelligence committee and the lead  impeachment manager. For many, he has become a familiar face of the proceedings, leading the investigation into the allegations against the president. He presided over the House impeachment hearings in the lead-up to the Senate trial, earning the scorn of Trump — and a nickname: "Shifty Schiff."

Nadler is chair of the House judiciary committee, which drafted the two articles of impeachment against Trump. Nadler was also a member of the judiciary committee during president Bill Clinton's impeachment in 1998. Nadler was an earlier supporter of a Trump impeachment, declaring last August that his panel would hold impeachment hearings related to special counsel Robert Mueller's Russia investigation.

A member of the House judiciary committee, Jeffries is also House Democratic caucus chairman. The former litigator is considered a rising star in the Democratic Party, and is seen as someone who could eventually replace Nancy Pelosi

A former U.S. Army Ranger who served in Iraq and Afghanistan who also worked as a lawyer, Crow is a freshman member of Congress. He is the only manager who is not a member of either the judiciary or intelligence committees, but, as the New York Times noted, is considered a leading voice on national security.

A former Houston judge and newly elected congresswoman, Garcia became one of the first two Latinas to represent Texas in U.S. Congress. She has also worked as a social worker, legal aid lawyer and as a city controller for Houston. She serves on the House judiciary committee.

A judiciary committee member, Lofgren, who has been in Congress for almost 25 years, is the only manager who was involved in the two other presidential impeachment proceedings, against Richard Nixon and Bill Clinton. Specifically, she worked on the congressional staff investigation of Nixon's impeachment. (Nixon resigned before he was impeached).

Demings is a member of both the judiciary and intelligence committees, but is the only manager without a law degree. However, she does have law enforcement experience. She worked for the Orlando Police Department for 27 years, becoming the force's first female police chief in 2007.

Trump's lawyers will present their case for the president and will be allowed to cross-examine the impeachment managers, along with any witnesses.

Cipollone is the current White House counsel, who advises the president on all legal matters. He leads Trump's defence team but has spent most of his career in commercial litigation and doesn't have extensive experience with trials. But he has worked on numerous high-profile cases, including the lawsuit against credit-reporting company Equifax after a massive data breach.

The personal lawyer to Trump, Sekulow also represented the president during the Mueller investigation. Sekulow hosts a radio talk show and is chief counsel for the American Center for Law and Justice, a non-profit that advocates for religious freedoms.

A former prosecutor and independent counsel, Starr's 445-page report formed the basis for the House impeachment of Clinton in late 1998. The former appeals court judge had been appointed to investigate the Clintons in relation to a real estate deal known as the Whitewater controversy, among other matters, but his probe widened to include Bill Clinton's sexual relationship with White House intern Monica Lewinsky.

The Harvard law professor has been part of the legal team for a number of high-profile defendants, including O.J. Simpson, Claus von Bulow, Jeffrey Epstein and Mike Tyson. A self-described Democrat, Dershowitz nevertheless says he doesn't believe the actions of the president necessitate his removal from office.

The former federal prosecutor succeeded Starr as independent counsel during the investigation of Clinton. But Ray declined to prosecute Clinton in connection with perjury and obstruction charges.

The former attorney general of Florida and a longtime Trump supporter, Bondi joined the White House communications team late last year on a temporary basis to help shape the administration's defence strategy around the House impeachment investigation. 

The former federal attorney has handled organized crime and racketeering cases, including the nine-month trial and conviction of the underboss of the New England Mafia. Raskin and her husband, Martin, were both part of Trump's legal team during the Mueller investigation.

Herschmann is a partner at Kasowitz Benson Torres LLP, a law firm that has represented Trump in numerous cases over the last 15 years. He's also a former assistant district attorney in the Manhattan District Attorney's Office.

The U.S. Constitution mandates that a Senate presidential impeachment trial be presided over by the chief justice of the Supreme Court, a position currently held by Roberts.

Appointed to the high court by George W. Bush in 2005, Roberts's role in the Senate trial is mostly ceremonial, as he has limited powers over the proceedings. He won't be ruling on objections, but he does have authority to hold someone in contempt, if, for example, a witness refuses to testify.

He can rule on the relevance of material, but the Senate majority can overrule him.