EVERETT — The Democratic Party’s Big Dog is returning to Everett.

Former President Bill Clinton is coming to Paine Field next month to fire up supporters of Democratic Sen. Patty Murray for the homestretch of the fall campaign.

Clinton’s visit Oct. 18 will come with voters already casting ballots in the contest between Murray and Republican challenger Dino Rossi, one of the most closely watched Senate races in the country.

The rally is set for 2 p.m. at Paine Field’s Flying Heritage Collection, 3407 109th Street SW. It is free and open to the public.

Before traveling to Everett, Clinton will dine for dollars with Murray at a private fundraiser at the Washington State Convention &Trade Center in Seattle.

Clinton is busy these days crisscrossing the nation to campaign for incumbent Democrats such as Murray who are locked in tight races and whose defeat could affect which party controls Congress in 2011.

This won’t be the first time Clinton and Murray have shared a stage in Washington state.

In 1992, as he ran for president, he held a rally in Seattle where Murray, then a candidate for U.S. Senate, joined him.

Five years later, President Clinton attended fundraisers in the same city for the first-term senator.

“In 1992, our nation faced so many of the same challenges we face today,” Murray said in a prepared statement. “President Clinton has always been a strong advocate for middle class families — the ones who work hard and play by the rules — and I am proud to stand by his side as we work on building a stronger America to help those families succeed.”

State Republican Party Chairman Luke Esser said the former president’s visit is a sign Democratic leaders view Murray as vulnerable this year.

“I’m not terribly surprised,” Esser said. “The D.C. establishment is trying to circle the wagons around Patty Murray. She’s going to be judged on the merits of her record and no former president is going to be able to nuance her around that fact.”

Clinton is the latest party heavyweight enlisted to lend Murray a hand this election.

President Barack Obama dropped into the Seattle area Aug. 17 and stayed long enough to raise several hundred thousand dollars for her campaign.

Vice President Joe Biden will be in Tacoma on Oct. 8 for a get-out-the-vote rally and first lady Michelle Obama is penciled in for an Oct. 25 stopover in Washington.

This will be Clinton’s second trip to Snohomish County.

He flew into Paine Field aboard Air Force One on Feb. 23, 1993 — just a month after he was sworn in as president. That visit was part of a cross-country swing to sell his economic plan to the American people. He also met privately with Boeing workers at a time of heavy layoffs.

He’s been to the state several times. Most recently, he came for a fundraiser for Sen. Maria Cantwell in 2006 and stumped for his wife, Hillary, during her presidential bid in 2008.

For the rally, reservations are not required,* though people are encouraged to “RSVP to help us gauge how much space will be needed,” campaign spokeswoman Julie Edwards said.

Reservations can be made online at www.pattymurray.com/snohomish.

For information, call 206-286-9199.

Reporter Jerry Cornfield: 360-352-8623; jcornfield@heraldnet.com.

* Correction, September 28, 2010: Reservations are not required, as this article originally stated. People are asked to make a reservation so organizers can gauge attendance.