“One of the big outstanding issues here is how did this all come about?” — Sen. Ron Johnson

The Wisconsin Republican wants to put Rep. Adam Schiff, the lead House impeachment manager, on the spot by honing in on any contacts he or his staff had with the anonymous whistleblower whose complaint kickstarted the impeachment probe.

Johnson’s question gets at a familiar refrain that has echoed through the conservative media sphere for months, fueled in no small part by the president himself. Trump claims Schiff wrote the whistleblower complaint himself, and his attorneys trumpeted such suspicions in a legal brief before the trial, arguing that the issue “remains shrouded in secrecy to this day.”

Schiff’s reply is likely to echo an explanation his spokesman delivered back in October, when he told The New York Times that the person coming forward — since identified as a CIA officer — approached the House Intelligence Committee with vague concerns about Trump’s Ukraine outreach and questions about how to report the matter.

The aide said such requests are typical and that the person was offered guidance on how to go through official channels. Some of that interaction was shared with Schiff, but the staffer didn’t identify the individual to the California Democrat.

“Did the House managers have any obligation to be truthful with what they put out? The way it came across is, they haven’t given us all the information.” — Sen. Rick Scott

The Florida Republican’s question reflects a common refrain heard by criminal defense attorneys during trials — that the evidence prosecutors presented to a judge or jury is selectively chosen to paint a misleading narrative.

House Democrats have addressed the topic during the trial, insisting that they’ve put into the Senate trial record the most relevant materials pertaining to their argument that Trump should be removed from office. They would likely repeat that explanation if the question comes up.

Pressing Schiff and company to address the subject could also open Republicans up to attacks that they are the ones limiting evidence, witnesses and other information in the Senate trial. Trump’s lawyers have also been accused of selectively choosing the information they presented during their arguments.

The questions legal experts want to ask

“I would ask the House managers why there is no article of impeachment based on the president’s obstruction of justice relating to the Russian interference investigation, which is a stronger basis for conviction and removal from office than either of the two articles before the Senate.” — Phil LaCovara, former Watergate attorney

Talk about touching a sore spot . Pressing the Democratic impeachment managers on their reasons for largely leaving the Mueller probe out of impeachment exposes internal party differences that have been largely papered over since December.

Many House members were indeed clamoring for the president’s attempts to stymie Mueller to inform an obstruction of justice impeachment article. But House Speaker Nancy Pelosi overruled the Mueller faction in deference to more moderate Democrats who wanted to keep the impeachment probe focused on the Ukraine scandal.

“In his call with President Zelensky, President Trump does not mention the problem of corruption in Ukraine. … What is your evidence that despite his words on the call, Trump acted because he was concerned about corruption?” — William Jeffress, longtime D.C. defense attorney

With the question, Jeffress would want to pressure Cipollone to explain the president’s true motivations in his outreach to the Ukraine.

All the evidence Democrats have collected and presented shows Trump was hyper-focused on political opponents like Joe Biden whenever he brought up corruption in Ukraine.