A combined version of two bipartisan Senate bills designed to protect special counsel Robert Mueller’s job is set to be released Wednesday, marking lawmakers’ latest political warning shot to President Donald Trump as he entertains firing the man investigating him.

The new Senate legislation is the product of months-long talks among Sens. Lindsey Graham (R-S.C.), Thom Tillis (R-N.C.), Cory Booker (D-N.J.) and Chris Coons (D-Del.), who introduced similar versions of Mueller protection bills last year. The success of their bipartisan talks was confirmed by two sources familiar with the discussions.

The senators’ final product would give any special counsel 10 days after a termination to challenge the move in court.

While the agreement among Graham, Tillis, Booker and Coons represents a key step forward in the legislative effort to deter Trump from firing Mueller, the legislation remains short of buy-in from Judiciary Committee Chairman Chuck Grassley (R-Iowa), who would have to steer it through his influential panel to the Senate floor. Grassley, who declared Tuesday that a Mueller firing would amount to “suicide” by Trump, has raised possible constitutional concerns but not ruled out eventual support.

Greg Sargeant is cautiously optimistic that Republicans MIGHT (finally) act as a barrier to Trump:

It is the timing of this bill that creates reasons for (very) cautious optimism. According to an aide to a Democratic senator on the committee, the feeling is that Tillis would have been unlikely to move forward with it unless he had received a signal that it might result in action. That’s because Tillis had sponsored one of the previous Mueller-protection bills, which didn’t go anywhere, and Tillis might not have any appetite for getting humiliated by a second failure.

Which means a great deal turns on what Grassley says today. Grassley claims it would be “suicide” for Trump to try to remove Mueller. Grassley now has an opportunity to prove he is actually prepared to act against this eventuality. Tillis’s willingness to move forward could signal that Grassley is willing as well, Democratic aides believe.

We’ll see if that comes to pass. But if the bill were to get voted out of the Judiciary Committee, it would pose a very stark test for McConnell. The Senate majority leader claimed on Tuesday, laughably, that he doesn’t see any “clear indication” of the need for legislation, because he doesn’t think any effort to remove Mueller is “going to happen.” Would McConnell prevent a vote on a bill to forestall that possibility if it showed signs of momentum?

The absurdity of McConnell’s argument points to something that has always been puzzling about this debate. If Republicans were to act now, it would make it less likely that Trump would either try to remove Mueller or succeed at it. They themselves say they don’t want that outcome to come to pass. Yet they won’t act to make that less likely on the grounds that it probably isn’t going to happen.

But we already know that Trump has repeatedly tried to remove Mueller in the past. We know he is seriously considering taking various steps that might accomplish this. And, crucially, we know he has been testing what he can get away with. Note this key revelation from The Post today:

Within the president’s orbit, people described Trump as furious and “lit up” by the recent developments, and floating a trial balloon to test the boundaries of trying to halt Mueller’s burgeoning probe.

“His anger is unabated,” said a Republican strategist in frequent touch with the White House, who added that the mood there is “extremely grim.”

If Trump is “testing the boundaries,” then why would he not conclude that there are no boundaries as long as Republicans refuse to say what the consequences of crossing this line will be? If Trump does take this plunge, their predicament could get more difficult, not less. The pressure on them to take even more drastic steps against Trump will increase. Yet at the same time, Trump’s base may rally more vigorously behind the president against Mueller, making acting even harder. Why not act now with a more modest step in order to make a much more explosive clash later less likely?

It is always possible, of course, that Republicans don’t actually intend to act if Trump does go full authoritarian. The fate of this new Mueller-protection effort will send a clear signal as to their true intentions.

Hope to get a copy soon.