President Donald Trump's ploy to bully Senate Republicans into dropping a longstanding rule about presidential nominations appears to have crashed and burned, Politico reported on Tuesday — with lawmakers holding their ground against him in a way they generally dare not do.

The drama began in July, when Trump lashed out at 91-year-old Senate Judiciary Chair Chuck Grassley (R-IA), calling him "weak and ineffective" and demanding he axe "blue slips," the tradition that committees must have the approval of a nominee's home state senators to advance a nominee.

Republicans already weakened blue slip rules for circuit court nominees in 2017, which is how Trump's former personal lawyer Emil Bove got a circuit court appointment earlier this year despite objections from both of New Jersey's senators. But they have been adamantly against eliminating them for district court judges or executive nominations.

Grassley pushed back, taking umbrage at Trump's "personal insults" against him, and the broader Senate GOP caucus followed suit. According to Politico, there's no sign of the GOP backing down — they may tinker with nomination rules to speed up confirmations on the Senate floor, but they won't eliminate blue slips or weaken the committee vetting process.

Unlike in many other cases of resistance against Trump, where GOP lawmakers have given quotes anonymously, some senators are being quite open in rebuffing the president, with Sen. John Kennedy (R-LA) telling Politico, “As a practical matter, the Senate’s not going to give up the blue slip. So my appeal to the president is: please reconsider. Why do we want to have this fight for nothing?”

There's a key reason GOP senators don't want to undermine their rules for Trump's benefit here, strategists told Politico: they know it would backfire on them.

Mike Fragoso, a former adviser to Sen. Mitch McConnell (R-KY), "argued that even Republicans wary of crossing the president now have taken advantage of the blue slip policy when Democrats held power. He added that there are relatively few bench seats in solidly Democratic states that Trump could even fill now without consent from Democrats," noted the report. This means Trump would get very few judges nominated by totally eliminating blue slips, but a future Democratic president could flood red states with district court judges of their own.

Beyond judges, however, Trump is being stymied by blue slips when it comes to appointing federal prosecutors.

Senate Minority Leader Chuck Schumer (D-NY) has blocked Jay Clayton's confirmation to be U.S. Attorney for the Southern District of New York, while New Jersey's senators have blocked another personal Trump lawyer, Alina Habba, for the prosecutor office there, prompting a standoff where Trump's Justice Department has skirted rules and reversed decisions of local judges to install her on an acting basis.