In a courtroom blocks from Capitol Hill, a parade of Washingtonians called to jury duty last week pondered a question for a cynical age.

Is it really a crime to lie to Congress if Congress is doing something silly at the time?

The men and women were potential jurors in the retrial of legendary baseball pitcher Roger Clemens, who is charged with lying when he denied using performance-enhancing drugs before a House committee in 2008.

“I just assume there are other things we could be doing,” said one, who said he works in computer systems for Fannie Mae and follows Notre Dame football.

Another, who said he worked as a bioengineer, called the proceedings “excessive.”

“I thought Congress would have more important matters that pertained to more people than focusing their efforts on those hearings,” he said.

Clemens’s defense team and government lawyers spent four days last week picking a jury, and that work will continue Monday before opening statements are set to begin in the District’s federal court.

As the prospective jurors submitted to question after question about Clemens and Congress, the courtroom became a kind of impromptu focus group on the legislative body that defines and bewilders their city. Many wondered why Congress was spending its time investigating a game and the things in one player’s bloodstream.

“Strange use of Congress’s time,” said one prospective juror, an art historian at the Smithsonian Institution. Another, from an environmental nonprofit group, said it wasn’t “a great use of taxpayer money.”

“There are a thousand other things that hurt kids more than performance-enhancing drugs,” the Notre Dame fan said. Jurors were identified not by name but by a court-assigned number.

This question of whether Congress was wasting its time will have crucial legal value in this case. Prosecutors from the District’s U.S. Attorney’s Office not only must prove that Clemens lied to the House panel — but also that his alleged lies were “material” to congressional action.

Prosecutors suggested to potential jurors that the hearings were material to Congress’s concerns that children might be influenced by the conduct of professional athletes.

The pitcher’s defense team will probably argue that they weren’t. Clemens’s first trial was halted quickly because of a prosecutor’s error, but it lasted long enough for Clemens’s lawyers to start sketching out a “What was Congress thinking?” defense.

“What legitimate investigative purpose is served by asking a private citizen if they ever used a controlled substance?” Clemens’s lead lawyer, Rusty Hardin, asked former House parliamentarian Charles W. Johnson, who had been called as a witness on the legislature’s ways during his first trial last year.

This time around, the job of discrediting Congress may have gotten easier. The gridlocked, divided body has slipped to historic lows in popularity: The latest Washington Post/ABC News poll showed only 13 percent of Americans approved of its job performance.

“One of the hurdles the government has to overcome is answering, ‘Why the heck are we involved in this type of investigation?’ ” U.S. District Judge Reggie B. Walton said last week, out of earshot of the potential jurors.

Clemens’s charges stem from a hearing before the House Committee on Oversight and Government Reform. At that time, Clemens had recently been named as a user of banned substances, after an investigation by former senator George Mitchell.

Beforehand, a member of the committee, then-Rep. Christopher Shays (R-Conn.), said he warned Clemens of the consequences of lying.

“He came and met privately with me, and I said, ‘Don’t testify, because if you tell a lie, you will be prosecuted,’ ” Shays recalled Friday. He lost his seat to a Democrat in 2008. “He was adamant that he wasn’t lying. He wanted to clear his name.”

Congressional experts said that Congress wasn’t doing anything wrong back then. And it certainly wasn’t doing anything unprecedented: That body’s power to investigate is considered to be as broad as its power to legislate, which means it can look into almost anything it wants.

“Congress can’t investigate just for the sake of exposure. So if people are interested just in what the Kardashians are doing . . . then, if there’s no conceivable legislative purpose, then that would be an abuse of the congressional investigation power,” said Lance Cole, a professor at Penn State who has studied congressional inquiries through the years.

But baseball, Cole said, is different: It’s an important economic engine, which enjoys a special antitrust exemption that could be revoked by Congress.

So it was fair game, he said: “This is well within — to use baseball terminology — the sweet spot of congressional investigations.”

In the past, Congress has used its broad investigative power to do great good: A century ago on April 19, the Senate began taking testimony from the survivors of the Titanic, which had sunk five days earlier. That investigation led to new legislation that made ships safer.

Congress also has used its investigative power to make its own members look important. This month, four different congressional committees are looking into the spending scandal at the General Services Administration.

“Just a bunch of people with two-by-fours hitting pinatas,” said Norman J. Ornstein, a congressional scholar at the American Enterprise Institute.

Ornstein, for one, thinks that the 2008 Clemens hearing — along with congressional hearings on steroids in 2005 — was more useful that these prospective jurors may remember.

“What Congress did in this case was to turn a much sharper spotlight onto the problems here, with the abuse of steroids,” he said. “In significant part as a consequence of those hearings, you saw a sport beginning to clean itself up.”

Staff writer Del Quentin Wilber contributed to this report.