The Note: Trump allies forced to play defense as impeachment moves to Senate

The TAKE with Rick Klein

Impeachment is out of the House and on to the Senate -- belatedly but decisively, and with all that the delays have meant.

But the tests for President Donald Trump's team and his allies have barely begun. The start of a trial brings the opportunity as well as the necessity for the president's side to mount a defense, as opposed to simply questioning the legitimacy of the enterprise.

The pomp and procedures of a Senate trial, beginning Thursday when House managers present articles of impeachment to the Senate, will require more than talking points. So will votes on document and witness requests that will feature formal roll-call votes presided over -- not by Vice President Mike Pence -- but by Chief Justice John Roberts.

"The Senate is on trial as well as the president," House Judiciary Chairman Jerry Nadler, one of the impeachment managers, said Wednesday.

A piece of the political argument for impeachment was always to put pressure on Republicans to defend Trump's actions publicly. That's a challenge to the president's legal team -- and for his extended political team, up to and including Republican senators.

The RUNDOWN with MaryAlice Parks

Following Tuesday's debate in Iowa, Sen. Elizabeth Warren's team said they felt good she was forcibly making an argument about her electability. By talking about the electoral success of other female candidates and making a case that she can talk to all parts of the party and country, Warren tried to take the issue of her electability head on. After all, it is an issue that has continued to haunt her campaign. Even some of her most strident supporters say they worry she may not be able to win in a general election.

The Warren campaign kept the messaging going Wednesday, releasing a list of 40 voters who they say voted for Trump in 2016, but are now planning to vote for her. The campaign provided quotes from the voters in their announcement, reportedly talking about Warren building a coalition and fighting for all working families.

Sen. Bernie Sanders' team argued instead that he is best positioned to reach out and inspire new voters to go to the polls, and his campaign clearly plans to hammer that point home as a point of comparison with the other Democratic candidates in the months ahead.

When asked about whether he thought Warren could expand the base of Democratic voters like they think he can, Sanders' senior adviser, Jeff Weaver, told ABC News, "Bernie Sanders is uniquely positioned to expand the base in terms of bringing in new people and working-class people into the political process, bringing in incredible numbers of young people, particularly young people of color."

Time will soon tell which candidate is indeed better at this. Either way, it is clear, Democrats know they need to bring new people into the fold to grow their party, not simply run up the score in blue hubs.

The TIP with Will Steakin and Kendall Karson

Former Rep. Joe Walsh, the long-shot primary challenger to Trump, is set to take his qualms regarding canceled GOP primary contests to the doors of the Republican National Committee headquarters on Thursday.

Walsh, who's also been promoting a recently announced book, said he plans to bring supporters and activists to the Washington, D.C., offices to protest the Republican state parties canceling primaries, which he calls "nakedly anti-democratic."

So far, six Republican state primaries have been canceled and just the president will appear on four others. Iowa Republicans still plan to hold their caucus in a few weeks.

THE PLAYLIST

ABC News' "Start Here" Podcast. Thursday morning's episode features ABC News Senior Congressional Correspondent Mary Bruce on the next steps in the Senate after the House formally delivered the impeachment charges against President Donald Trump. Then, ABC News' Patrick Reevell in Moscow breaks down Russian President Vladimir Putin's proposed constitutional changes and how it could affect his term limits. http://apple.co/2HPocUL

ABC News' "Powerhouse Politics" podcast. Tuesday night in Iowa was a status quo debate in a world where a whole bunch of campaigns like their status. ABC News Chief White House Correspondent Jonathan Karl and ABC News Political Director Rick Klein break down the state of the race now that the last debate before the caucuses is over. And former Sen. Trent Lott, the Senate majority leader during President Bill Clinton's impeachment trial, speaks with Karl as Trump's impeachment trial is set to begin next week. https://apple.co/2RgxmLL

FiveThirtyEight Politics Podcast. In a late-night installment of the FiveThirtyEight Politics podcast, the crew reacts to the final Democratic primary debate before the Iowa caucuses. The candidates spent time debating foreign policy and whether a woman can beat President Donald Trump in the 2020 presidential election. https://apple.co/23r5y7w

WHAT YOU NEED TO KNOW TODAY

Download the ABC News app and select "The Note" as an item of interest to receive the day's sharpest political analysis.

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