“It’s beyond petty,” said Rhode Island Sen. Jack Reed, the top Democrat on the Armed Services Committee, which would be the first stop in Shanahan’s confirmation process once Trump nominates him. “It’s disgraceful and the White House should be embarrassed.”

“It certainly doesn’t inspire any confidence in his leadership,” a Senate Democratic aide said, adding that the incident “raises concerns” about whether Shanahan — unlike former Secretary Jim Mattis — could deflect White House efforts to politicize the military.

“This is pathetic,” said Sen. Tim Kaine (D-Va.), another Armed Services member.

A spokesperson for Republican Sen. Lindsey Graham (R-S.C.), who was close friends with McCain and is an ally of the president, said the South Carolina senator is in touch with the Navy asking for clarification.

“It’s important to Senator Graham that the McCain family knows what happened, if anything,” Kevin Bishop, Graham’s spokesperson, said in an email.

Former military leaders demanded answers about how such a plan was allowed to get as far as it did, calling it an insult to a ship that had already stricken by tragedy. (10 of the McCain’s sailors died in 2017 after a collision with a merchant vessel.) And they said those responsible need to go.

“[Shanahan] ought to take responsibility no matter what, and he ought to demand that whoever in the White House made this request be fired,” former Navy Secretary Ray Mabus said in an interview. “Whether he knew about it or not, declining to take responsibility in his initial reaction ought to be looked at carefully” by Congress during Shanahan’s upcoming confirmation hearing.

Retired Army Gen. Barry McCaffrey went even further, calling for Shanahan’s head to roll if he had been aware of the White House request.

“Did Acting Sec Def Shanahan know the White House gave instructions to hide the name of a US Navy warship and the sailors ID? IF SO HE SHOULD RESIGN,” tweetedMcCaffrey, who also served as drug czar in the Clinton administration.

The Wall Street Journal, which broke the story Wednesday night, reported that Shanahan was aware of the plan to either hide the ship or move it from port.

But Shanahan initially told reporters Thursday that he learned about the effort through media reports and declined to comment further. He later said he would never dishonor the memory of the late Sen. John McCain and promised to get to the bottom of what happened.

The Journal said the Navy placed a tarp over the stern of the ship to hide its name and told crew members to take the day off so they wouldn’t be around when Trump visited the base on Monday night Eastern time. The Navy has since said that the tarp was removed the Saturday before Trump arrived and the ship was in a “normal configuration” during the visit. A Navy official who asked not to be named said the crews of the McCain and the destroyer USS Stethem “were not among commands selected” to go to Trump’s event, and were off as part of a 96-hour Memorial Day liberty period.

Still, Trump appeared to confirm Thursday that someone in the White House had made the request — and he repeated his well-known dislike for the Arizona senator.

“Now, somebody did it because they thought I didn’t like him, OK? And, they were well-meaning,” the president told reporters.

But Trump said he himself never made any such request. “I would never do a thing like that,” he said.

Trump later tweeted that the Navy had “put out a disclaimer” on the story. “Looks like the story was an exaggeration, or even Fake News - but why not, everything else is!”

Shanahan, after denying knowledge of the incident, said he has tasked his chief of staff with finding out who knew what and when. Yet critics say Shanahan is responsible for the military’s actions.

“This is certainly going to come up in Shanahan’s confirmation hearing,” said Price Floyd, a former Pentagon spokesperson in the Obama administration who also did White House advance travel work with the State Department. “Advance guys work for the man” — meaning the president — “but it’s egregious that any staffer would think they need to move a ship because of its name,” he said.

“In my time as an advance person, I couldn’t imagine asking to do something like that. It’s beyond the pale,” Floyd added.

A former senior military officer with experience in the Pacific said such a micromanaging of ship movements by a member of the White House staff would be a striking breach of the military chain of command.

“It would be extraordinary for higher levels to influence those types of movements of individual ships,” said the former officer, who spoke on condition of anonymity. “I don’t know how this happened but I certainly never saw anything like that in my career.”

Shanahan became acting secretary Jan. 1 after Mattis, a seasoned Marine four-star general known for slow-walking or diverting some of Trump’s decisions, resigned over the president’s decision to pull troops from Syria. Shanahan then openly lobbied for months to get the secretary job permanently, before Trump announced plans to nominate him May 9.

But Trump has yet to make the nomination official.

And before this latest incident, Shanahan was already facing headwinds: Senators were already furious over Trump’s decision to sell weapons to Middle Eastern countries over the objections of Congress, and his declaration of a national emergency in order to divert billions in military funds toward the border wall.

Now he can add the destroyer McCain to the list of questions he will almost certainly face during his Senate hearing.

Still, many lawmakers will probably be willing to believe that Shanahan didn’t know of the plans for the destroyer, said Mackenzie Eaglen, a defense expert at the American Enterprise Institute.

“The timing is not great but absent hard evidence to the contrary, most members will be amenable to taking the acting secretary at his word on this matter,” she said.

Regardless of what Shanahan knew about the McCain, high-ranking retired officers and government officials said he is making a mistake in asking his chief of staff to investigate the incident. That’s a job better suited to the Defense Department’s inspector general, Mabus and others said.

“If neither the president nor the secretary of defense were aware of this, which they maintain, they should find out who did take such shameful actions and hold them accountable for a profound lack of judgment,” said retired Adm. James Stavridis, former NATO supreme allied commander. “A DoD IG investigation would be a logical place to start.”

The investigation would have to involve senior military leaders, so it’s not appropriate for Shanahan’s office to investigate, said retired Lt. Gen. David Barno.

Some wanted to know how the plan got as far as it did without someone hitting the brakes. The Journal said the idea to hide the ship began with the White House Military Office, then was communicated to Navy officials in the Pacific.

“It’s a disturbing episode that brings up the issue of the degree to which the military is being used as a political prop and politics being injecting into military activities,” Barno said, adding that the White House office “has no authority over military commanders.”

“Why didn’t anybody who received this guidance object to this earlier, at the combatant command, at 7th Fleet, at the two-star level in Yokosuka?” Barno continued. “Saner minds prevailed, but before that, how did it make its way down the entire chain of command?”

Kelly Magsamen, a former senior Obama Pentagon official who worked closely with Pacific Command, said she was dumbfounded.

“I’m flabbergasted that anyone in the chain of command tolerated the request and began to implement it, that they even got halfway down the road on this stuff,” she said. “This request would never have been made under any other president, and if it had, the military chain of command would have pushed back significantly, and if they feel they can’t or won’t under this administration, that’s very troubling.

“It suggests to me there’s something wrong in the military leadership ranks right now that these types of events continue to occur — something beyond just Trump,” Magsamen said.

Retired Rear Adm. Mark Montgomery, a former operations officer with U.S. Pacific Command, said he was most troubled by the slow response between when one part of Pacific Command received the request and began to act on it on May 15, and when someone removed the tarp 10 days later — based on the timeline outlined in the initial news reports.

“Nearly everyone should understand it’s not appropriate to try to eliminate or marginalize the presence of a ship or ship’s company because of the name of the ship,” he said.