From the start, the courtroom drama in the impeachment trial of Ken Paxton, the Texas attorney general, has centered on a confrontation between the larger-than-life Houston lawyers brought in by each side to argue the case.

In Mr. Paxton’s corner, there is Tony Buzbee, a well-tanned orator and onetime candidate for mayor of Houston, who successfully defended Rick Perry, a former governor of Texas, against charges of abuse of office.

Not to be outdone, the House impeachment managers brought in their own big guns: Dick DeGuerin, whose list of clients included the Waco cult leader David Koresh, and Rusty Hardin, a defender of criminally accused athletes like Roger Clemens and Scottie Pippen.

The voices of these high-profile lawyers have echoed for days in the towering chamber of the Texas State Senate, underscoring the unusual nature of the case. The impeachment trial, now expected to wrap up by week’s end, is the first of a statewide official in Texas in more than a century, and it has become a showcase for the deepening rifts within the Republican Party, both in the state and nationally.

The first days of the trial have included clashes over evidence and accusations of grandstanding between Mr. Hardin, an avuncular 81-year-old, and Mr. Buzbee, 55, whose aggressive cross-examination appeared to rattle the prosecution’s first witness.

“He’s asking for hearsay,” Mr. Hardin said of Mr. Buzbee at one point, smiling as he objected from his seat. “It must be a valid objection — he made it 30 times when I was talking.”

“I don’t know what that objection is,” Mr. Buzbee replied, shifting his weight at the lectern, his arms folded.

Mr. Hardin chuckled loudly.

“Let’s just move on, gentlemen,” said Lt. Gov. Dan Patrick, who is presiding over the impeachment trial.

The two lawyers have faced off before, most notably over sexual assault accusations against Deshaun Watson, a former Houston Texans quarterback, with Mr. Hardin defending Mr. Watson and Mr. Buzbee representing the accusers. The case ended in a settlement and a resumption of Mr. Watson’s football career.

The two lawyers present a sharp contrast in styles. Mr. Buzbee, whose hair is tightly slicked back, has proudly described himself as “a shark” and has occasionally sought elective office, including during the impeachment trial: After being named to Mr. Paxton’s legal team, he announced that he would run for Houston City Council in the November election. A few days before the trial, Mr. Buzbee also announced the launch of a business, selling a cannabis-derived seltzer product called HoBuzz.

Mr. Hardin’s more understated style attempts what Texas Monthly once called a “practiced informality,” aimed at making juries feel as comfortable as possible. In the courtroom, he favors tan suits rather than navy or gray, and his opening statements tend to be brief.

“If you’re going to ask twelve people to make a miserable decision, don’t make them miserable while you’re doing it,” he told the magazine for a profile in 2002.

At the same time, Mr. Hardin, a one-time prosecutor in Houston, has a reputation for aggressiveness that earned him the nickname “Bulldog” and drove Anna Nicole Smith, a former Playboy model, to lash out at him during six days of testimony in a 2001 court battle over her dead husband’s estate. Mr. Hardin represented the estate.

“Screw you, Rusty,” Ms. Smith told him from the witness stand when he suggested that her tears had been the result of acting lessons. For years afterward, Mr. Hardin has said, he was playfully greeted by shouts of the phrase.

Mr. Hardin appeared to stick to his tried and true approach at the start of the Paxton trial, adopting a calm tone as he presented the first witnesses. He did not deliver the prosecution’s opening statement, which was given instead by Representative Andrew Murr, chair of the House board of impeachment managers. Mr. Murr kept his statement well under the allotted 60 minutes.

Mr. Buzbee, in his opening statement for the defense, came out swinging, attacking the process and questioning the motives of the assembled state senators who are acting as the jury.

“Cases are supposed to be decided only upon the evidence,” Mr. Buzbee said. “But I do wonder, are we really going to get a fair trial here? Have you already decided, based on what is politically expedient, or what’s best for you personally?”

Later, Mr. Buzbee aggressively cross-examined the first witness, Jeff Mateer, a former top aide to Mr. Paxton who believed that his boss was committing potentially criminal acts and went to the F.B.I. with those concerns in 2020. At one point, after hours on the witness stand, Mr. Mateer grew agitated.

“I know you’re getting excited, just let me finish,” Mr. Buzbee said. “Take it easy.”

“You’re trying to misstate things,” Mr. Mateer said.

“Let’s be clear about what you did, about what you did, the loyal servant, trusted friend,” Mr. Buzbee said sarcastically.

Mr. Hardin objected that Mr. Buzbee was “making fun of the witness” in his questioning, and accused him of interjecting “commercials” for his side of the case.

“Again, let’s just move on,” Mr. Patrick said.

Mr. Buzbee took on cross-examination duties on Monday, making light of the first extended testimony about an extramarital affair that Mr. Paxton had, and Mr. Paxton’s efforts to conceal the affair from his staff and from his wife Angela, who is a state senator. Ms. Paxton is sitting in on the impeachment trial but is not allowed to take part in the deliberations.

The extramarital affair caused clear alarm in the attorney general’s office, where Mr. Paxton’s chief of staff, Katherine Minter Cary, said she warned him that it could make him vulnerable to bribery. In testimony on Monday, Ms. Cary described a 2018 meeting at Mr. Paxton’s campaign headquarters, in which the attorney general apologized for the affair and Ms. Paxton, who was with him, cried. “My heart broke for her,” Ms. Cary said. Mr. Paxton won re-election later that year.

One of the articles of impeachment accuses Mr. Paxton of abusing his office to benefit an Austin real estate developer, Nate Paul. Prosecutors say Mr. Paul was helping Mr. Paxton conduct the affair, which they say continued after the 2018 apology.

Mr. Buzbee was dismissive.

“Imagine if we impeached everybody here in Austin that had had an affair,” he said. “We’d be impeaching for the next 100 years, wouldn’t we?”

Even when other lawyers took up the questioning, the weight of legal and Texas history remained. At one point on Friday, both of the lawyers doing the questioning — Mr. DeGuerin and Dan Cogdell, a Houston lawyer who is representing Mr. Paxton in a separate criminal case — as well as the witness who was testifying, David Maxwell, the former director of law enforcement in Mr. Paxton’s office, had been involved in some way in the Waco siege.

“This is a Super Bowl for trial lawyers,” Richard Leach, who sat in the spectators’ section of the gallery on Monday, said of the impeachment trial. He and his wife, Gloria Cantu Minnick, both lawyers, drove from Houston to watch the proceedings, eager to see some of the state’s best-known legal firepower on display.

Mr. Buzbee and Mr. Hardin represent different generations of Texas lawyers. They are both military veterans, but they served in very different eras: Mr. Hardin as an Army captain in Vietnam, Mr. Buzbee as a Marine Corps infantry officer in the Persian Gulf and in Somalia.

Other Texas lawyers watching the trial have expressed admiration for their successes while taking note of their different styles.

Mr. Hardin is “old school” and “more straightforward,” while Mr. Buzbee tends to display “flash and razzmatazz,” said Kenneth Tekell, a defense lawyer for energy companies. “Rusty paints inside the lines,” he added. “Buzbee paints all over the place. He tries to be more colorful.”

Mr. Hardin, who was a Harris County prosecutor for 15 years before going into private practice, has won favorable verdicts for a number of prominent athletes. Mr. Clemens, a former major league pitcher, was acquitted on charges that he obstructed justice and lied to Congress by denying that he had used performance-enhancing drugs.

One of Mr. Buzbee’s best-known victories was his successful defense of Mr. Perry, who was ultimately cleared of charges that he had abused his power as governor. Another prominent client was the singer Jimmy Buffett, whom Mr. Buzbee successfully represented in a trademark dispute nearly two decades ago.

“Buzbee is a really smart and aggressive lawyer who has scrapped his way to the top, or at least what he perceives to be the top,” said Bob McIntyre, 76, a close friend of Mr. Hardin who has been a Houston lawyer for 50 years.

Still, Mr. Buzbee’s talent for aggressive advocacy may have led to the lieutenant governor’s decision to impose a gag order before and during the impeachment trial. In a news conference shortly after he was named to be Mr. Paxton’s attorney, Mr. Buzbee blasted the impeachment charges as “baloney.”

Neither Mr. Hardin nor Mr. Buzbee granted a request for an interview for this article, though if the past is any indication, they might have liked to.