But what makes the job easier for moderator does not necessarily make it easier for candidates.

There are a series of specific questions on which the 12 candidates must strike the right balance. For instance: Can candidates express unease or disapproval of Hunter Biden’s lucrative work on the board of a Ukrainian energy company — something many Democrats believe is a genuine embarrassment — without looking like they are embracing President Donald Trump’s own assault on the Biden family?

These specific questions point to a broader challenge. If one measure of power is the ability to set the agenda — what are people talking about? — the debate at Otterbein University in suburban Columbus threatens to codify a dynamic that has been lurking for months: The most powerful agenda-setter in the Democratic Party is none other than Donald Trump.

Historically, the people who have won the presidency have been people who reframed the national conversation around their big ideas, big personalities, or ability to channel big movements in the direction of history.

In the Trump worldview, as long as people are talking about him — even if the talk is how much they loathe him — he is winning. At a minimum, it confronts aspiring Democratic presidential candidates with a challenge as they try to make themselves outsized figures who can capture public imagination and set the agenda.

In each case, the barrage of developments since September will offer new windows into how candidates can talk about Trump while avoiding talking about nothing but Trump — a harder course to navigate than meets the eye. Among the subjects to watch:

Impeachment

There presumably will be no voice on the stage ready to state what a significant portion of Democratic strategists believe: that it would be better to skip House impeachment of Trump altogether and just beat him in a general election, especially since there is so little chance he would be convicted by the Senate and some unknown chance that he would emerge politically stronger. This cautious approach is simply not where most Democratic voters are.

At the same time, there is a choice for candidates about how closely they wish to align themselves with the House effort, or how much advice they wish to give on important procedural questions. Those questions include how quickly House Democrats should move, whether an impeachment inquiry should be narrowly about Trump’s efforts to draw Ukraine into investigating Joe Biden, or more broadly about alleged abuses of power on other subjects.

More broadly, do candidates look to embrace the passion of impeachment advocates in the House, or strike a more detached stance toward the House proceedings? This is the first debate since House Speaker Nancy Pelosi was pulled out of her own previously detached stance to begin impeachment proceedings.

Trump and Syria

Even Republicans have denounced Trump’s decision to pull U.S. troops out of Syria, effectively inviting a Turkish incursion and abandoning Kurdish forces who have been U.S. allies. Senate Majority Leader Mitch McConnell said he was “gravely concerned” that the move would revive ISIS and Trump ally Sen. Lindsey Graham called it “a disaster in the making.”

This would suggest the topic is easy pickings for Democrats to lambaste Trump as both immoral and incompetent in his conduct of foreign policy. Still, it is worth being alert to the specific words and tone Democrats strike in this area.

Almost no important national security or foreign policy voice is supporting the precipitous manner in which Trump executed his policy shift. But his underlying philosophy — that it is time to pull back U.S. military commitments abroad and stop “endless wars” — is in fact one that has ample support in both parties.

This gives an opportunity — including for Biden, with the most extensive experience in foreign policy debates — to both denounce Trump and make a more affirmative statement about their own worldview.

The Biden family

For nearly a month now, it’s been one of those Washington parlor games that won’t really have a right answer until we hear more from voters — either in the form of multiple unambiguous polls or, this winter, once caucus and primary voting begins. There’s a chance that Trump’s attacks on the Biden family actually help the former vice president, allowing him to portray himself as the victim of a Trump smear and the person the president is most afraid of.

There’s also a chance that Hunter Biden’s business dealings in Ukraine, an area in which he brought no previous expertise or evident value other than his last name, solidify the perception of the Democratic hopeful as representative of a self-dealing Washington culture who is too tired, too conventional, and too compromised to take the fight to Trump.

Lots of Democrats worry about the latter. But it is not yet clear the rewards are there for Biden’s rivals to say this out loud on the debate stage.