WASHINGTON » As the Senate edged toward a nasty filibuster vote on Chuck Hagel’s nomination to be defense secretary, Sen. Ted Cruz, R-Texas, sat silent and satisfied in the corner of the chamber — his voice robbed by laryngitis — as he absorbed what he had wrought in his mere seven weeks of Senate service.

Hagel, a former senator from Cruz’s own party, was about to be the victim of the first filibuster of a nominee to lead the Pentagon. The blockade was due in no small part to the very junior senator’s relentless pursuit of speeches, financial records or any other documents with Hagel’s name on them going back at least five years. Some Republicans praised the work of the brash newcomer, but others joined Democrats in saying that Cruz had gone too far.

Without naming names, Sen. Barbara Boxer, D-Calif., offered a biting label for the Texan’s accusatory crusade: McCarthyism.

"It was really reminiscent of a different time and place, when you said, ‘I have here in my pocket a speech you made on such and such a date,’ and, of course, nothing was in the pocket," she said, a reference to Sen. Joseph R. McCarthy’s bloody pursuit of communists in the 1950s. "It was reminiscent of some bad times."

In just two months, Cruz, 42, has made his presence felt in an institution where new arrivals are usually not heard from for months, if not years. Besides suggesting that Hagel might have received compensation from foreign enemies, he has tangled with the mayor of Chicago, sandbagged the Senate’s third-ranking Democrat on national television, voted against virtually everything before him — including the confirmation of John Kerry as secretary of state — and raised the hackles of colleagues from both parties.

He could not be more pleased. Washington’s new bad boy feels good.

"I made promises to the people of Texas that I would come to Washington to shake up the status quo," he said in emailed answers to questions in lieu of a speaking voice. "That is what I intend to do, and it is what I have done in every way possible in the responsibilities that have been granted to me."

In a body known for comity, Cruz is taking confrontational Tea Party sensibilities to new heights — or lows, depending on one’s perspective. Wowed conservatives hail him as a hero, but even some Republican colleagues are growing publicly frustrated with a man who has taken the zeal of the prosecutor and applied it to the decorous quarters of the Senate.

Sen. Lindsey Graham, R-S.C., said that some of the demands Cruz made of Hagel were "out of bounds, quite frankly." Sen. John McCain, R-Ariz., issued a public rebuke after Cruz suggested, with no evidence, that Hagel had accepted honoraria from North Korea.

"All I can say is that the appropriate way to treat Sen. Hagel is to be as tough as you want to be, but don’t be disrespectful or malign his character," McCain said.

Democrats were more blunt.

"He basically came out and made the accusation about money from North Korea or money from our enemies, and he just laid out there all of this accusatory verbiage without a shred of evidence," said Sen. Claire McCaskill, D-Mo. "In this country we had a terrible experience with innuendo and inference when Joe McCarthy hung out in the United States Senate, and I just think we have to be more careful."

Cruz, a Canadian-born lawyer who won an upset primary victory last year, is adamant in his own defense. He said his focus at hearings had been on policy, not personality. With Hagel, whose nomination is set for a Senate vote the week of Feb. 25, he said his request for financial disclosures were backed by 24 other senators. As for his statement that Hagel may have received honoraria from nefarious sources, "the suggestions I have made in my arguments have been merely to raise examples for why I believe Sen. Hagel’s financial disclosure is so important," he said.

"Comity does not mean avoiding the truth," he added. "And it would be wrong to avoid speaking the truth about someone’s record and past policy positions, even if doing so inevitably subjects me to personal criticism from Democrats and the media."

To the growing core of ardent conservatives in the Senate, Cruz has offered a jolt of positive energy.

"If you don’t ruffle any feather, you’re not doing anything right," said Sen. Rand Paul, R-Ky., who garnered similar attention in his opening weeks in the Senate two years ago.

Cruz was among the 22 senators who voted against reauthorizing the Violence Against Women Act, among the 34 who voted against raising the debt ceiling, among the 19 who tried to cut off military sales to Egypt, among the 36 who opposed a relief package for the regions hit by Hurricane Sandy, and among the three senators who voted against Kerry’s confirmation, as he looked on.

"I was compelled to vote no on Sen. Kerry’s nomination because of his longstanding less-than-vigorous defense of U.S. national security issues," said Cruz, who also questioned the commitment of Kerry and Hagel to the armed forces, though both served in Vietnam and he has no record of military service.

Chris Chocola, the president of the Club for Growth, a conservative free-market political action committee that strongly backed Cruz in his victory last year against the establishment’s favorite, Lt. Gov. David Dewhurst, said the new senator was doing precisely what he had expected. The growing caucus of "pro-growth" conservatives — Cruz, Paul, Marco Rubio of Florida, Patrick Toomey of Pennsylvania, Jeff Flake of Arizona, Mike Lee of Utah, Ron Johnson of Wisconsin and Tim Scott of South Carolina — has begun reshaping what it means to be a Republican in the Senate, he said.

"The last thing we need is another status quo senator or congressman who will go along to get along," said former Sen. Jim DeMint of South Carolina, who pumped money into Cruz’s campaign, then left the Senate to lead the conservative Heritage Foundation.

Last month, Cruz faced off aggressively with Sen. Charles E. Schumer of New York on a Sunday talk show. When Mayor Rahm Emanuel of Chicago wrote to the chiefs of big banks urging them not to invest in gun manufacturers, Cruz followed up with letters criticizing the "bullying" of a political "Godfather."

After she raised the specter of McCarthyism, McCaskill was asked if she had spoken to Cruz about her concerns.

"I’m not sure it would do any good," she said. "Do you?"