As things stand, there isn’t a whole lot Senate Democrats can do to block Donald Trump’s most extreme judicial nominees. Filibusters on would-be jurists are no more, and urging Senate Republicans to keep the president’s worst nominees off the federal bench doesn’t seem to work.

Blue slips, however, still exist. It’s a rather obscure, century-old rule, but it works in a fairly straightforward way: in order for a judicial nominee to get a confirmation hearing in the Senate Judiciary Committee, he or she needs approval from both of the senators from the nominee’s home state. (They need to, in a rather literal sense, return a blue slip to the committee, allowing the process to continue.) In practical terms, that creates trouble for this White House if a nominee comes from a state with two Democratic senators.

For example, Trump has nominated Minnesota’s David Stras for the 8th Circuit Court of Appeals, but he doesn’t have the support of Minnesota’s Senate delegation. According to the standards and traditions of the chamber, that means Stras can’t get a hearing and can’t be confirmed.

And so, it was jarring to see this Politico report the other day, explaining that Republicans no longer feel like honoring blue slips.

Senate Judiciary Committee Chairman Chuck Grassley is burning the blue slip for some judicial nominees. The Iowa Republican announced Thursday that he is going ahead with a confirmation hearing for a nominee to the powerful appellate courts despite the objections of a Democrat who had been blocking the nomination for months. The move will likely escalate the judicial wars in the Senate.

Ya think?

In the Obama era, the Senate Judiciary Committee was led by Pat Leahy for six years, and the Vermont Democrat honored the blue-slip tradition: if two Republican senators from a given state balked at a nominee, Leahy wouldn’t give that nominee a hearing, even if the GOP senators were motivated by nothing but partisan reflex.

When Chuck Grassley took over the committee, he praised Leahy’s handling of the issue and said he’d honor the blue-slip tradition. Democrats believed him and expected the Iowa Republican to follow through. Leahy himself said in reference to Grassley, “I trust him to keep his word.”

He did – until last week.

At least for now, blue slips aren’t completely dead. Grassley said he still intends to honor them for district court nominees, but appellate court nominees are, evidently, a different story.

The consequences of the move will unfold fairly quickly, with Senate Republicans finding it even easier to approve any and all Trump judicial nominees. And as a matter of principle, this serves as a reminder that the parties appear to be playing by two very different sets of rules.

Postscript: For more background and history on blue slips, the estimable Sarah Binder, a poli-sci professor at GW, wrote a good piece for the Washington Post over the weekend. Slate’s Dahlia Lithwick had a related item in September.