What Is a 'Blue Slip'? The Senate Custom Trump Wants Gone

It is, literally, a piece of blue paper. When a president nominates someone to be a federal district judge or a U.S. attorney, the Senate Judiciary Committee mails one to each of that nominee's two home-state senators. They can sign it favorably, sign it unfavorably, or simply not send it back. No statute requires any of this. No rule of the Senate demands it, either. It is a courtesy that has governed judicial nominations since at least 1918, and in 2026 it is the single biggest obstacle standing between Donald Trump and the courts he wants to fill.

By late June, the standoff had frozen entire slates of nominations in states with at least one Democratic senator, and it had put President Trump and the Republican who chairs the Judiciary Committee, Iowa's Chuck Grassley, in open conflict — over a custom neither man's own party created and neither can simply repeal.

How a blue slip actually works

The mechanics are almost quaint next to the fight they're causing. After a president nominates someone for a district judgeship, a U.S. attorney post, or another position tied to a single state, the Judiciary Committee sends that blue-colored form to the two senators from the nominee's home state. A positive response from both signals the committee can proceed. A negative response — or silence, which the chair may treat the same way — has historically been enough for the chair to decline to schedule a hearing at all. There's no override vote required. The nomination simply doesn't move.

Circuit court nominees used to fall under the same courtesy, but that changed in 2017, early in Trump's first term, when the Republican-led committee — chaired by Grassley then, too — stopped honoring blue slips for the appeals courts. District judgeships and U.S. attorney nominations kept the old rule.

Why Trump wants it gone

The president's complaint is straightforward: in any state with one Democratic senator, a blue slip lets that single lawmaker functionally veto his nominee. "This is based on an old custom. It's not based on a law. And I think it's unconstitutional," Trump told reporters, adding that he was considering a lawsuit over the practice. He has aimed most of his frustration at Grassley personally, at one point telling him to instruct Senate Democrats to "GO TO HELL" over blocked nominees.

The clearest flashpoint has been New York, where Senate Minority Leader Chuck Schumer has declined to return blue slips for nominees to U.S. attorney posts, including in the Southern District of New York. According to reporting on the Judiciary Committee's June 18 business meeting, Trump has tied that standoff to unrelated administration priorities, saying he won't move on a new director of national intelligence or FISA reauthorization until he gets his Southern District of New York picks confirmed. In New Jersey, Democratic Sens. Andy Kim and Cory Booker used the same leverage against Alina Habba's nomination as U.S. attorney.

Why his own party won't go along with it

Here's the part that makes this fight unusual: the president isn't fighting Democrats over the blue slip. He's fighting Republicans who control the Senate. Grassley has held firm through months of public pressure, and other GOP senators have backed him. North Carolina's Thom Tillis called scrapping the custom "a terrible, short-sighted ploy that paves the path for Democrats to ram through extremist liberal judges in red states over the long-term," warning colleagues they "shouldn't fall for it." Majority Leader John Thune has said much the same, noting he used blue slips himself while negotiating a judicial vacancy with the Biden White House. Grassley posted a blunter version of the same math on social media, noting that Republicans used blue slips to keep roughly 30 nominees favored by Democrats off the bench during the Biden administration — seats now open for Trump to fill instead.

That's the trade at the center of the custom: whoever controls the White House wants it gone, and whoever doesn't wants it kept, which is exactly why it has survived more than a century of one-party control switching hands over and over.

Has this actually stalled confirmations?

By the numbers, yes, measurably. During the first Trump term and the Biden administration, senators from the opposing party returned blue slips on hundreds of district court and U.S. attorney nominees without much friction. During Trump's second term, according to reporting on the committee's June proceedings, blue slips have come back far less often — and for the first time on record, Senate Democrats have declined to let a single civilian nominee through by voice vote or unanimous consent, the fast-track methods that used to clear routine nominations without a floor fight.

Grassley has said he intends to keep honoring the custom for as long as he chairs the committee, which sets up a structural standoff no single hearing can resolve: the chairman controls the gavel, the White House controls the nominations, and neither controls the other's leverage. The same tension runs through other Senate customs that look procedural on paper and turn out to be load-bearing in practice — the kind of mechanism explored in how the Byrd Rule quietly limits what fits in a reconciliation bill or how a discharge petition can force a House vote leadership doesn't want.

Thune has floated taking up Senate rule changes this fall that would make it harder for the minority to slow nominations generally, separate from the blue slip fight itself. Whether that effort touches blue slips directly is still an open question — and it's the one Grassley has been the most consistent, and the most alone in his own party's leadership, about refusing to answer.