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"Hamilton Burger," left, couldn't get much past Perry.

She's seemed to have an answer to every question about any case and any subject.

Leave it to the newest senator, Saturday Night Live veteran and one-time radio host Al Franken of Minnesota to finally ask Supreme Court nominee Sonia Sotomayor something she couldn't answer during her confirmation hearing.

"What was the one case in Perry Mason that Burger won?" Franken asked just a short time ago.

He was referring to Hamilton Burger, the long-suffering district attorney in the long-running TV drama of the '50s and '60s.

Both Franken and Sotomayor profess to be huge fans of the show and to have watched it when they were young. Yet neither of them know the answer:

That other voice toward the end — who gets Franken to admit he doesn't know the answer to his own question — is Senate Judiciary Committee Chairman Patrick Leahy, D-Vt.

So what is the answer?

According to IMDB.com, the episode commonly known for being "the only time Perry Mason loses" was The Deadly Verdict, which was broadcast in 1963.

TV.com says that "Janice Barton is found guilty of the murder of her wealthy relative and sentenced to death." And, the website adds, "this was the only case in which Mason's client was found guilty, and sentenced to death. The outcry from the public was so severe that they never ventured down this road again."

But, as IMDB points out:

In the first-season episode The Case of the Terrified Typist, not only is Mason's client convicted of murder — he turns out to be really guilty! (However, Mason figures out that the murderer was impersonating someone else, and since some of the prosecution's evidence was related to the actual person whose identity had been stolen, a mistrial is declared, meaning a second trial for the defendant, presumably without Mason's services.)

In the sixth-season closer, The Case of the Witless Witness, a respected judge rules against Mason in some civil matter; when the judge ends up falsely accused of corruption, then murder, Mason doesn't hesitate to defend him.

Update at 7:55 a.m. ET, July 16. On All Things Considered last evening, co-host Robert Siegel spoke with Barbara Hale, who played Mason's long-time assistant Della Street on the TV series. She jokingly makes the case that Perry never really lost any of his cases — at least not when TV viewers could see: