Keller @ Large: How Impeachment Process Works

BOSTON (CBS) - Ever since the Watergate scandal engulfed the presidency of Richard Nixon in the early 1970s, the word pops up whenever a sitting president appears embattled or enmeshed in a legal controversy - impeachment, the process in our law that allows for the removal of a federal judge or elected official. But inquiring minds want to know - how, exactly, does impeachment work?

* Impeachment charges must be for "high crimes and misdemeanors," usually some sort of treason, bribery or obstruction of justice.

The charges have to be filed in the House, where it takes a simple majority vote to to move things along. Next up, a trial in the Senate, where a two-thirds majority is needed to convict. Note: the term "impeachment" refers to the House action, but both Presidents Bill Clinton and Andrew Jackson, while impeached, were acquitted in the Senate trial; Nixon was never technically impeached at all, resigning when a House vote to impeach appeared certain.

* What real chance is there we're about to see impeachment happen?

Pending further developments, history suggests it's too soon to tell. These things take time.

An independent counsel began investigating Clinton in 1994, more than four years before impeachment began. And almost two years elapsed between the Watergate burglary and the start of the Nixon impeachment process.

With Republicans now in control of the House and Senate, there would need to be intense political pressure - driven by their own constituents - before enough of them would back impeachment, and the evidence will have to be more definitive than just James Comey's word versus the president's.

* And another deterrent to impeachment - understanding what kind of damage it can do to our democracy.

Just look at what's happened to faith in government since Watergate.

Since 1991 when Gallup began asking the question, the percent of people expressing confidence in the presidency has collapsed from 72 percent to 36 percent. Confidence in Congress has been virtually non-existent for years, dropping from 42 percent before Nixon's impeachment to single-digits now.

How much lower can those ratings go? We may be about to find out