It's a beautiful thing: Trump is free, in his weakness, to retreat on a whim to red-state cocoons like West Virginia, where he and his co-dependent bitter-enders are free to indulge their delusional certitudes — but back in the real world, the bell is tolling ever louder. Because Robert Mueller is digging ever deeper into the corruptive rot at the core of Trump's regime.

We got word yesterday, from the "fake news" Wall Street Journal, that special counsel Mueller has taken the next major step in his farflung criminal probe — impaneling a federal grand jury in Washington, a veritable evidentiary machine that has the power to subpoena documents and witnesses. (This is in addition to a federal grand jury in Virginia that has long been tasked with probing Michael Flynn.) We also got word that the Washington grand jury is already issuing subpoenas in connection with Trump Jr.'s June '16 meeting with shady Russians, the meeting he took because they were dangling Hillary dirt.

And since Mueller — aided by 16 lawyer-investigators who specialize in global financial crimes — is reportedly digging into Trump's money dealings with Russia (ignoring Trump's warning not to dig there), the power to subpoena documents is crucial indeed. As ex-White House ethics lawyer Norman Eisen said yesterday, "Given Trump's refusal to produce his tax returns, he hasn't been subject to a true vet. He's about to get one."

But even as Mueller follows the money, he's also probing Trump's firing of FBI director James Comey — and whether it was a felonious attempt to obstruct justice by thwarting the Russia investigation. It appears that a slew of FBI officials are ready to testify that it most certainly was. (Thus buttressing what Trump freely admitted to NBC's Lester Holt on national TV.)

A senior law enforcement official says: "What you are going to have is the potential for a powerful obstruction case. You are going to have [Comey] testify, and then the acting director, the chief of staff to the FBI director, the FBI's general counsel, and then others, one right after another. This has never been the word of Trump against what [Comey] has had to say. This is more like the Federal Bureau of Investigation versus Donald Trump."

The FBI people are jonesing to cooperate. And the grand jury system is tough on witnesses who are loath to cooperate. This time (unlike on Capitol Hill), Trump apparatchiks and family members will be compelled to testify under oath — don't be surprised if you see a steady parade of them entering and exiting the courthouse in the months ahead — and if they blatantly lie (as Trump hirees instinctively do), they can be charged with perjury.

We should also point out that federal prosecutors typically impanel grand jury when they have strong reason to believe that indictments may well be warranted — and that federal grand juries agree to indict as high as 99 percent of the time.

Can a sitting president be indicted? Yup. Two decades ago, the conservative legal eagles working for Clinton nemesis Kenneth Starr concluded in a memo: "It is proper, constitutional, and legal for a federal grand jury to indict a sitting president for serious criminal acts that are not part of, and are contrary to, the president’s official duties. In this country, no one ... is above the law." But even if Trump escapes indictment, his entourage may not. A string of indictments would surely exacerbate his current political weakness, even among Republicans who've been reluctant to distance themselves.

In fact, we're starting to see some significant distancing. Two new Senate bills — unveiled with Republican co-sponsors — seek to protect Mueller from Trump's lawless wrath. Basically, the bipartisan bills are designed to make it more difficult for Trump to fire his pursuer. Republican Sen. Thom Tillis of North Carolina, one of the co-sponsors, said yesterday that he opposes "unmerited removals," and declared: "It is critical that special counsels have the independence and resources they need to lead investigations." (Translation: "I'm up for re-election in 2020, and there's no way I'm gonna let myself go down in flames with Trump.")

By the way, Trump attorney Jay Sekulow tells Fox News that "the president is not thinking about firing Robert Mueller." (Good to know, assuming Sekulow knows anything. Last month, he emphatically said on national TV that Trump didn't author his son's lying statement about the June '16 meeting with Russians; turns out, Trump authored it.) But Trump would take a major political hit if he tries to fire Mueller; according to a new national poll, 69 percent of Americans would call it an abuse of power.

So Trump can run his mouth all he wants, as he did in West Virginia last night, about how the Russia probe is "a total fabrication," about how it's a Democratic or media concoction that "makes them feel better when they have nothing else to talk about," and the naifs in MAGA caps can cheer all they want — but this grand jury business is for real, and fake rhetoric can't slow its machinery.

A harsh reckoning appears to be in the offing. As the British writer Aldous Huxley wrote a century ago, "Human beings are condemned to consequences."

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