Clinton is scheduled appear at the Seattle Center on June 3 for a conversation about the First Amendment, the Seattle Times reported.
McDermott is embroiled in a civil suit, filed by an Ohio Republican, about whether a taped phone call by Republican Rep. John Boehner about a pending Ethics Committee probe of then-House Speaker Newt Gingrich should be considered free speech.
Gingrich had been publicly promising not to organize opposition to the ethics probe, and the recorded conversation suggested he was violating his pledge.
In 1997, a Florida couple gave McDermott the tape, which he leaked to The Atlanta Journal-Constitution and The New York Times, the Seattle Times said.
Legal experts say it's possible McDermott's Seattle home, assessed at $781,000, could become involved if McDermott loses the lawsuit.
Last month, McDermott asked the full nine-member U.S. Court of Appeals to take the case after a three-judge panel ruled against him.
The appeals court ordered McDermott to pay Boehner about $700,000 -- $60,000 in damages and more than $600,000 in legal costs.