Special counsel Robert Mueller's investigation into the Trump team's ties to Russia took another crucial step Thursday, with the empaneling of a grand jury in Washington.

The Wall Street Journal reported Thursday that special counsel Robert Mueller has empaneled a grand jury in Washington as part of his probe into Russia’s interference in our election, and possible collusion on the part of the Trump campaign.

As the Journal notes, this is a sign that “Mueller’s inquiry is ramping up and that it will likely continue for months.”

Ty Cobb, special counsel to Donald Trump, told the paper that the administration “favors anything that accelerates the conclusion” of the investigation, and that they are “committed to fully cooperating with Mr. Mueller.”

Which is an interesting development, considering the White House’s past treatment of Mueller.

Trump’s team and surrogates went into immediate attack mode when Mueller was appointed as special counsel, engaging in a coordinated and repugnant smear campaign against him.

They hinted at a lack of confidence in Mueller’s ability and impartiality, with Newt Gingrich going so far as to characterize the probe as “witch hunt.”

The White House’s typical disarray was put on public display when Attorney General Jeff Sessions told the Senate Intelligence Committee that he personally had confidence in Mueller and would not seek to dismiss him from the job, just days before Trump lawyer Jay Sekulow claimed on national television that Mueller’s investigation was “not constitutional.”

He was wrong, of course, and certainly Mueller himself knows that better than a Trump crony trying to defend his indefensible president.

Empaneling a grand jury shows that Mueller is taking this task extremely seriously, and that he may use the process to subpoena records, call witnesses to testify, and truly dig down to the very bottom of this ever-deepening scandal.

It is high time for Republicans in Congress to speak out against the attacks by the Trump team on Mueller, and to make it clear which side they are on: Trump’s or America’s.