Trump's Supreme Court nominee argued that presidents should be shielded from criminal investigations

WASHINGTON - Starting with Watergate in the 1970s, four presidents - Richard Nixon, Ronald Reagan, Bill Clinton and now Donald Trump - have faced criminal investigations into their actions led by special prosecutors. For Nixon and Clinton, those inquiries led to impeachment charges in Congress.

But Brett Kavanaugh, Trump's nominee to the Supreme Court, has argued these special investigations are a mistake and may well be unconstitutional. Although he was a key player in the investigation of Clinton, Kavanaugh has since concluded that a sitting president should be accorded temporary immunity from any criminal investigation while in office.

To say a president cannot be indicted is not unusual. Most legal scholars agree the only remedy for a president who breaks the law and commits "high crimes and misdemeanors" is impeachment by Congress. Only after leaving office may a former president be criminally prosecuted, they say.

But Kavanaugh has taken the view of presidential immunity a step further than most. He argues that