The Note: New squabbles further muddle run-up to Iowa

The TAKE with Rick Klein

They can’t agree what the next two weeks will be about. Yet they’re forced to agree it may not be about them.

Tuesday brings the substantive start of a Senate impeachment trial that will draw four presidential contenders off the campaign trail. With no answers coming for a while on witnesses, the trial could conceivably last beyond Feb. 3 – when the Iowa caucuses start the Democrats’ nomination process.

A tour around the messaging landscape shows the left taking on the center, the left taking on the left, and the women in the field positioning themselves against the men.

The four top-tier contenders see the potential company of a fifth, to say nothing of the two candidates who can afford to wait a while to see things sort out.

A squabble is developing over Social Security, to add to one about campaign fundraising and one about gender and electability. All of those fights involve different pairs of candidates -- and, in one case, a candidate who isn’t competing in any states that vote before March.

For all that, we’re still waiting on a negative Democrat-vs.-Democrat ad.

A mild campaign is heading for an unpredictable finish -- with an opponent looming on the other side who is anything but mild and definitely unpredictable.

The RUNDOWN with Mary Alice Parks

We know they will stash their cellphones off the Senate floor and prepare to listen, quietly, for hours on end. We know little else for sure.

Just before 1 p.m., we expect the House trial managers to enter the chamber, followed by the president’s defense team and then Supreme Court Chief Justice John Roberts. The impeachment resolution is expected to be read out loud, in its entirety as the trial of President Donald Trump gets underway.

Opening statements from both sides will likely not begin until Wednesday as both parties plan to spend much of Tuesday hashing out the rules which will dictate the rest of the proceedings. And there is plenty to debate there: motions, witnesses, debate time, breaks and whether to kick the cameras out all together and go into closed session.

The debate about how to conduct the trial looks like it’s going to be messy, let alone the trial itself.

There is a strong likelihood senators could be looking at extra long days -- maybe even 12 hours -- as Senate Majority Leader Mitch McConnell continues to signal he hopes to fast-track the process.

The TIP with Kendall Karson

Nearly three weeks before the next Democratic debate, Andrew Yang finds himself in familiar territory. The lone candidate of color with any major support in the primary field missed the cut for the January matchup in Iowa by only two polls. With the thresholds for the January and Feb. 7 debates largely remaining intact, he is once again two polls shy of reaching the polling requirement, according to an ABC News analysis.

For the early February debate -- hosted by ABC News, WMUR and Apple News -- Yang appears to be the only Democrat closing in on qualifying, having cleared the donor mark. But in order to avoid the same fate as January, he has one other shot: a new pathway that allows any candidate with a single national delegate to clinch a spot on the stage -- making the stakes for him to deliver a strong finish in Iowa that much higher.

Less than half of likely Democratic caucusgoers have made up their minds in the most recent Des Moines Register/CNN poll. And Yang is betting on that lack of decisiveness.

"Iowans are still very much up in the air, trying to figure out who they're going to support," he said in Iowa City on Saturday. "We've got 17 days here in Iowa make our case to people."

THE PLAYLIST

ABC News' "Start Here" podcast. Tuesday morning’s episode features ABC News’ Trish Turner, who tees us up for the resumption of President Donald Trump’s impeachment trial -- she says to expect bickering from both sides over the rules of trial before the opening arguments. Then, ABC News Senior Foreign correspondent Ian Pannell checks in from Beirut amid violent clashes between authorities and anti-government protestors. And, ABC News’ Kyra Phillips previews Trump’s trip to the World Economic Forum in Switzerland. http://apple.co/2HPocUL

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