This was originally published in the November 13 edition of CNN's Meanwhile in America, the daily email about US politics for global readers. Sign up here to receive it every weekday morning.

The turning point in public opinion that costs Donald Trump his presidency could come today -- at least, that's what Democrats hope. Millions will watch US officials testify in hearings to establish whether the President abused his power by trying to coerce Ukraine into meddling in a US election.

The first televised impeachment hearings are an attempt to shatter the conventional wisdom that Senate Republicans will never vote to oust Trump. To do that, Democrats will need to replicate moments from the storied Senate Watergate hearings in 1973 that burned President Richard Nixon's crimes into the mind of a nation.

In other words, they'll need their own John Dean or Alexander Butterfield: Dean was the then-White House counsel who encapsulated the scandal, testifying that he told Nixon "there was a cancer growing on the presidency," while little-known White House aide Butterfield revealed the taping system that doomed Nixon's presidency. "I was aware of listening devices," Butterfield said.

Credible witnesses like Bill Taylor, the top US diplomat in Ukraine, could have a similar impact this time. But Republicans on the House Intelligence Committee will do everything they can to thwart any such moment by setting off distractions and diversions designed to confuse viewers.

Democrats have struggled to stop previous high-profile hearings from turning into circuses, and this time they have made sure witnesses will first be questioned by professional counsel from both sides — at least delaying politicians' hijinks. In the social media age, the hearings will be on repeat for days on Twitter or Facebook, offering plenty of incentive for mischief.

If the witness testimony disappoints, it may be up to lawmakers to define the scandal for posterity. Nearly half a century ago, that job fell to Howard Baker, the top Republican on the Senate Watergate Committee, who uttered a phrase that now echoes through every presidential scandal: "What did the President know and when did he know it?"

Would any Republican nowadays ask a question so injurious to a President of their own party? The field is open for any starring player to define this impeachment drama -- and to write their own name in history.