Another potential scandal has cast a pall over Trump’s presidency, and as has become a learned behavior in the Republican Party, the vast majority of GOP officials are declining to speak out against him.

But their non-responses also speak volumes.

After a whistleblower complaint released Thursday alleged President Trump’s misdeeds with regard to Ukraine, reporters set about getting reaction from Republican elected officials. They ran into a stone wall.

As CNN’s Ted Barrett summarizes, many Republican senators claimed they hadn’t even read the relatively brief document, despite it having consumed the political world. But even those who said they had weren’t ready to completely dismiss the idea that there’s something amiss here.

A sampling from Barrett’s report:

- Tennessee Sen. Lamar Alexander said he has not read the complaint. “I’m waiting for the intelligence committee to finish its work.
- Ohio Sen. Rob Portman said he said he’s been “running around” all day and hasn’t read it and would not comment.
- Arkansas Sen. Tom Cotton said “no comment” twice and boarded a senators-only elevator when asked if he was concerned the White House was locking down information.
- Missouri Sen. Roy Blunt, a member of the Senate Intelligence Committee, said, “We’re committed to gather the information before we reach conclusions. Other people who don’t have this responsibility can reach conclusions right away,” Blunt said. “In my case I’m not ready to make any conclusions yet and still ready to gather more information.”
- Florida Sen. Marco Rubio told reporters he has read the whistleblower’s complaint, and says he has “more questions than answers.”

The responses from GOP senators were, as is typical of the upper chamber, somewhat more cautious than from other Republicans. Some reportedly even said they were declining to comment because they might one day be jurors at an impeachment trial in the Senate (which is a pretty amazing response).

But even considering that, the non-responses are unusual and remarkable. The GOP response de rigueur before midweek was to ignore questions about whether Trump did anything wrong and emphasize that his concerns about Joe and Hunter Biden’s actions in Ukraine were warranted — suggesting the whole thing was just about getting Ukraine to root out actual, real corruption.

That seemed to shift Thursday though, especially in the Senate, where Republicans seemed genuinely skittish about mounting anything like real defense of Trump. A few of them have criticized Trump for his Ukraine interference, including Sens. Mitt Romney (R-Utah), Ben Sasse (R-Neb.) and Patrick J. Toomey (R-Pa.), the last of whom called Trump’s call with Ukraine’s president “inappropriate” but not impeachable. Yet the rest of them don’t really seem too comfortable firmly taking the other side: that this is a nothingburger.

It’s difficult not to read that as evidence of genuine concern about what lies ahead. Even if Republicans truly think nothing bad happened — or that it wasn’t bad enough to cause the party problems — there is so much we don’t know at this point. And judging by Trump’s behaviors in the past, do any of them really want to gamble that what eventually comes out won’t make their initial defenses look foolish? We have a president who on that call with Ukrainian President Volodymyr Zelensky talked about all the United States does for Ukraine, and then immediately launched into asking for a “favor,” before pushing for two specific investigations that carry obvious domestic political benefits for him. Even if there may never be an explicit quid pro quo, Trump was unquestionably asking for foreign assistance in his reelection campaign.

The whistleblower also alleges relatively widespread concern within the administration and even a coverup attempt involving trying to bury the rough transcript of Trump’s call with Zelensky. They said it was put on a codeword-level computer system that is intended for sensitive national security information — not politically sensitive materials.

While we don’t know much, there are plenty of obvious avenues for investigation here. And for a president who was doing all this literally as the Robert S. Mueller III-Russia investigation was wrapping up, it suggests Trump wasn’t overly careful.

The best GOP pushback against the whistleblower at this point appears to be that their information is “secondhand,” which it is. Anytime a witness to something is getting information from someone else, it is subject to other people’s faulty recollections, misunderstandings and misinterpretations. We shouldn’t assume all of it is true.

But what we do know — the Trump-Zelensky call — is very accurately summarized in the complaint, despite the whistleblower not having been on it. And the whistleblower says they verified their secondhand allegations with multiple U.S. officials. Their understanding of intelligence matters and classification rules also suggest they are hardly a novice. And it is an intelligence official’s job to carve through misinformation to find the truth.

For all those reasons, it shouldn’t be surprising that top Republicans aren’t leaping to Trump’s defense. Romney said it well the other day when explaining why Republicans weren’t criticizing Trump.

“I think it’s very natural for people to look at circumstances and see them in the light that’s most amenable to their maintaining power, and doing things to preserve that power,” Romney said at the Aspen Festival.

The fact that these Republicans can’t yet see this in such a favorable light — and apparently don’t think leaping to Trump’s defense is a good move when it comes to preserving their power — speaks volumes.