Thursday’s Senate Judiciary Committee meeting may be remembered as this year’s high-water mark for those promoting the most ambitious aspects of the Obama gun control package. It will also be remembered as a milestone in the education of an unrepentant Ted Cruz.

During his first 10 weeks as the junior senator from Texas, Cruz has leveraged almost every available opportunity to burnish his reputation as the most intellectually rigorous and rhetorically forceful of this year’s tea party congressional newcomers. So far, his strategy for achieving quick and approving prominence on the right seems to be working; Cruz has been selected to deliver the keynote speech on Saturday night at the annual Conservative Political Action Conference.

At the same time, his confrontational style has rattled many of the more senior Republicans in the Senate. They worry that his reliance on pedantic questioning and unsubstantiated claims — both on full display during his battle against Chuck Hagel as secretary of Defense — will not only harm his effectiveness as a policymaker but also drag the bar for senatorial comity to a new low.

Democrats are eager for that first GOP concern to be proved true. And they share the other anxiety about the coarsening of Capitol discourse. So they are becoming ever-more openly scornful toward the 42-year-old former Texas solicitor general. Twice in as many days, two of the best-respected and longest-serving Senate Democrats made it plain to Cruz that, after less than three months, they were losing patience with his impertinence.

Cruz’s response to both California’s Dianne Feinstein and Maryland’s Barbara A. Mikulski was, in effect, too bad for you.

“I’m not a sixth grader,” Feinstein bristled after Cruz asked her a seemingly rhetorical question about whether a Bill of Rights that would prohibit sales of specified weapons would also allow a finite roster of books to be outlawed or a list of people who could be searched at will.  “I’m not a lawyer, but after 20 years I’ve been up close and personal with the Constitution,” she continued. “I am reasonably well educated, and I thank you for the lecture.”

After her bill to restrict new sales of semi-automatic rifles was approved, Feinstein sought to be magnanimous, apologizing to Cruz for her tone, if not her text. “You sort of got my dander up,” she said. But Cruz would only go so far in return. While he tipped his hat to Feinstein’s commitment to her cause, he declared it “unfortunate that a question about the Constitution provokes such a strenuous response.”

The Wednesday stare-down with Mikulski was not as heated because it was all about the time-honored norms of behavior on the Senate floor. But those with an ear for the sounds of annoyance inside the world’s greatest deliberative body could not mistake Mikulski’s message: It was time for Cruz to learn to mind his manners.

“There was no agreement to do round-robin here,” Mikulski replied after Cruz asked permission to take a break from his own spending bill speech so that one of his best GOP friends, Utah’s Mike Lee, could jump in line and avoid a scheduling crunch. “I wish to follow the traditional regular order, where the senator from Texas, the proponent of the amendment, has full and ample time, then other senators respond, and then Sen. Lee. I am not going to make a scene, but that is the way we usually do it.”

Did Cruz reply to that brushback by ending his speech, making life easier for his buddy and sending a signal that he’d learned a lesson? No. He said he had 10 minutes’ more talking to do, and he kept right on going.