The Senate Judiciary Committee Thursday approved legislation aimed at protecting special counsel Robert Mueller from being fired without cause by President Donald Trump.

Even the measure's opponents issued stark warnings to the president that any move to dismiss the special counsel would be political suicide and might lead to impeachment.

Four Republicans joined with all of the Democrats on the panel - a 14-7 vote - to approve the measure that would allow a court to decide whether t a termination was valid and possibly reverse it.

“Because special counsel investigations only occur where there is a conflict of interest within the executive branch, special counsel investigations are usually matters of great national concern,” chairman Charles Grassley said, as he knowingly bucked GOP Senate leadership in bringing up the bill.

“Transparency and accountability are in the public interest,” Grassley said, adding, “While my constitutional concerns remain, I believe this bill should be considered by the full Senate.”

But Senate Republican Leader Mitch McConnell recently said in no uncertain terms that he will not bring the bill up for consideration by the full body.

Republicans repeatedly said they do not believe the president will fire Mueller, but the chamber’s most senior Republican, Utah’s Orrin Hatch, while voting against the bill for what he said was its unconstitutional structure, warned Trump, “Firing Mueller would cause a firestorm and bring the administration’s agenda to a halt and could even result in impeachment.”

All of this happened just after the president, in a phone interview on Fox News, called Mueller’s investigation a “witch hunt,” as he has done repeatedly, and warned, “What’s going on with people in the Justice Department that shouldn’t be there -- they have a witch hunt against the President of the United States going on – I've taken the position – and I don’t have to take this position and maybe I'll change – that I will not be involved with the Justice Department.”

Sen. Mike Lee, R-Utah, a former Supreme Court clerk, while failing to secure enough votes for his own non-binding resolution that said that Mueller should be left alone to do his job, admonished his colleagues on passing a bill that he said violated the separation of powers between the executive and legislative branches and was “fundamentally at odds with the Constitution.”

“Why are we doing this?” Sen. Lindsey Graham, R-S.C., a co-author of the protection bill, asked rhetorically, “Because nobody in this country is above the law...We’re not saying you can’t fire somebody, but we’re saying somebody is going to look over your shoulder.”

Graham then asserted something that runs directly counter to what the White House has maintained, perhaps foreshadowing a difficult battle ahead should the president decide to fire the special counsel, saying, “The president cannot personally fire Mr. Mueller.”

"It’s about ensuring that no one man or woman in our system is above the law," said Sen. Chris Coons, D-Del., who helped author the measure with Graham and Sens. Thom Tillis, R-N.C., and Cory Booker, D-N.J.

Grassley, at the last minute, added new reporting requirements to the bipartisan measure, ensuring that Congress will - in the current and all future special counsel investigations - receive a report at the start and finish of any investigation, regardless of whether or not the probe recommends or seeks prosecutions.

And while the measure stands no hope in this current Senate, supporters said they hope an important message was sent to the White House today that any move to fire the special counsel would provoke a political backlash in Congress.

"Given President Trump’s statement just this morning that he may interfere with the special counsel’s investigation, it’s become even more of an imperative that Leader McConnell put this bill on the Senate floor for a vote immediately," said Senate Democratic Leader Chuck Schumer.