The Trump administration's latest defense for the infamous June 2016 meeting between top campaign aides and a Russian lawyer promising damaging information about Hillary Clinton is now dragging the Secret Service into the fray — and forcing the apolitical agency to wade into a politically explosive scandal.

The new controversy began Sunday, when Trump lawyer Jay Sekulow made an odd comment on ABC’s This Week while trying to explain away the fact that Donald Trump Jr., Jared Kushner, and then-campaign manager Paul Manafort attended the meeting. The session is widely seen as evidence of collusion between the campaign and Russia.

“I wondered why the Secret Service, if this was nefarious, why did the Secret Service let these people in?” Sekulow told Jon Karl. “The president had Secret Service protection at that point. That raised a question with me.”

The Secret Service wasn’t going to take that sitting down. In a rare rebuke, it answered Sekulow’s question — and implicitly said he was wrongly trying to use the agency as a political weapon. "Donald Trump Jr. was not a protectee of the USSS in June 2016," the agency responded in a statement to CNN. "Thus we would not have screened anyone he was meeting with at that time."

It shouldn’t be surprising that Trumpworld got caught in its latest attempt to wave away the meeting. After all, Sekulow's line is the latest in a series of ever-shifting excuses offered by Trump Jr. et al. about what actually happened during the June 2016 meeting and why it took place.

More than that, it shows that even important US security agencies are willing to openly contradict those who defend the president when they tell obvious untruths.

The explanations for the June 2016 meeting keep changing

My colleague Zack Beauchamp has a quick summary of the different explanations used by those trying to defend the Trump campaign for why top members decided to meet with a Kremlin-connected lawyer:

First, Trump Jr. denied any meeting with Russians. When the New York Times reported last Saturday [July 8] that he had met with Russian attorney Natalia Veselnitskaya, he said it was “a short introductory meeting” about “a program about the adoption of Russian children” — which is code for lifting Magnitsky sanctions. When the Times reported in a Sunday [July 9] follow-up that Trump Jr. went to the meeting to get dirt on Clinton, he admitted this was right — that Veselnitskaya was “an individual who I was told might have information helpful to the campaign,” but didn’t mention any potential Russian government connections. On Tuesday [July 11], to preempt yet another Times scoop, Trump Jr. published his emails with British publicist Rob Goldstone about the Veselnitskaya meeting — in which Goldstone states that the meeting was “part of Russia and its government’s support for Mr. Trump” and Trump Jr. replies that “if it’s what you say I love it.” Now, on Friday [July 14], Trump’s camp has admitted there was at least one more person at the meeting that we didn’t know about — and it seems plausible that this person, [Rinat] Akhmetshin, has at least some kind of connection to Russian intelligence.

Now, Sekulow’s comments weren’t meant to describe what happened in the meeting, but he did try to downplay the malicious nature of the gathering.

In effect, if the Secret Service had said the Russian lawyer and the others she brought with her to the meeting posed no security threat, he argued, then the whole thing may not have been as sketchy as it appears.

But now we know the Secret Service did no such vetting of those who met with Trump Jr., Kushner, and Manafort for a simple reason — it wasn’t the agency’s job to do so.

(There’s also the separate issue that the Secret Service would likely not have investigated the purpose of the meeting even if Trump Jr. had been under agency protection; the agency’s mandate would be to see whether the Russians posed a security risk, not whether they were there to quietly collude with the campaign.)

It’s interesting to note that the president and those around him keep angering security services in their employ over Russia-related events. Trump has famously rejected the intelligence community’s unanimous assessment that Moscow mounted a systematic effort to help Trump win the White House.

He also infuriated many FBI agents by firing former FBI Director James Comey for refusing to drop a probe into disgraced former National Security Adviser Michael Flynn and then being photographed laughing about the ouster during an Oval Office meeting with visiting Russian officials.

In this case, Sekulow piqued the Secret Service so much it chose to publicly contradict him on national television.

Time will surely reveal what else happened at — and who else attended — the June 2016 meeting. Until then, it would be wise of Trumpworld to stop openly denigrating the men and women of America’s law enforcement and intelligence communities, and those charged with protecting the president and his family. They deserve better.