The Note: Democrats target audience of 4, while GOP focuses on audience of 1

The TAKE with Rick Klein

There's the famous audience of one. Then there's the less-known audience of four.

President Donald Trump's attorneys may not have come off as particularly impressive in the early going of the impeachment trial. But that matters almost not at all so long as Trump is satisfied -- and his main show, with his team's opening arguments, is yet to come.

Democratic House managers may have offended some Republican senators by seeking to shame them into inviting witnesses and demanding documents. But that also won't matter so long as their message can be heard among the tiny handful of GOP senators whose votes on the matter aren't preordained.

What Democrats are trying to accomplish in the impeachment trial is almost shockingly narrow. Their main goal is to keep an investigation alive -- primarily by calling as witnesses a series of individuals who either do or recently did work in the Trump White House.

As a practical matter, that means convincing four Republicans – not 53 – to join them. And Republicans have long since calculated that the best way to keep those 53 together is to keep the president who leads and defines their party satisfied.

"If we don't stand up to this peril today," Rep. Adam Schiff, the lead House manager, told senators Wednesday, "we will write the history of our decline with our own hand."

That's an explicit plea for history to guide the actions of senators. But there remain very different interpretations of what the history of the Trump era will say.

The RUNDOWN with MaryAlice Parks

Sen. Elizabeth Warren is itching to take on former New York City Michael Bloomberg. Wednesday she objected to his continued ownership of his namesake news outlet.

"If Michael Bloomberg wants to be the Democratic nominee, he should let reporters do their jobs and report on him, and everyone else, as they see fit. And he should divest from Bloomberg News so there's no question about his influence over news coverage of presidential candidates," she tweeted after there was buzz about whether he was getting unfair favors -- as in no negative coverage -- from the organization.

Warren and Bloomberg have traded some of the most direct and personal jabs in the race so far. A few days ago an especially curt Bloomberg said Warren had nothing else to talk about after he was asked about her earlier statements that former female employees engaged in mediation with his company be let out of their non-disclosure agreements.

"I've taken more than a thousand unfiltered questions from the press and from voters since I got in the race," Warren wrote on Wednesday, and you could read the frustration leaping off the Twitter page.

Unless he gets a delegate in Iowa -- a state he is not competing in -- he will not be on the next debate stage. That means, once again, she and others will take questions without him.

The TIP with Kendall Karson

An historic impeachment trial might be confining the four sitting senators in the presidential contest to the nation's capital -- miles from Iowa and off the trail -- but fulfilling an oath to their current office is not impeding their efforts to assume a higher one.

Leading up to the Iowa caucuses, less than two weeks away, the candidates are leaning into their signature brands -- the markers that distinguish them and their campaigns from the rest, through any and all unconventional tactics.

Warren's campaign is releasing a video series -- billed as "Big Structural Conversations" -- to highlight the fight at the crux of her campaign: rooting out corruption. Minnesota Sen. Amy Klobuchar's husband and daughter are working their Midwestern chops by hosting "Hotdish House Parties" across Iowa and Klobuchar was partaking in her first Iowa "Tele-Town Hall" on Wednesday. Vermont Sen. Bernie Sanders is deploying his star-powered surrogates to Iowa -- such as Rep. Alexandria Ocasio-Cortez -- and embracing his indie political brand -- with help from filmmaker Michael Moore and a collection of musical guests for rallies and caucus concerts that could rival a music festival, including Bon Iver, Vampire Weekend, Mike Posner and Portugal. The Man.

THE PLAYLIST

ABC News' "Start Here" Podcast. Thursday morning's episode features ABC News' Katherine Faulders on the House impeachment managers beginning to argue their case against President Donald Trump. Then, ABC News' Chris Francescani joins the podcast after he was in the courtroom for opening arguments in Harvey Weinstein's rape and sexual assault trial. http://apple.co/2HPocUL

FiveThirtyEight Politics Podcast. President Trump's impeachment trial is underway, and the political strategies of both Democrats and Republicans are on clear display. In this installment of the FiveThirtyEight Politics podcast, Perry Bacon Jr. and Amelia Thomson-DeVeaux discuss those strategies and whether any senators will cross party lines in the final vote. https://apple.co/23r5y7w

ONE MORE THING

As Americans watch the ongoing impeachment trial of President Donald Trump in the Senate, there’s a lot going on behind the scenes that viewers aren’t likely to see on camera. ABC News' team of congressional reporters and correspondents saw several notable moments Tuesday and Wednesday, including contraband like crossword puzzles and Apple watches.

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The Note is a daily ABC News feature that highlights the day's top stories in politics. Please check back tomorrow for the latest.