Nearly 20 years after he left Congress, Carlton R. Sickles is trying to prove that older is necessarily better.

Sickles, lanky and vigorous at age 64, has a unique qualification for his bid to become the next congressman for the 8th District: As a Prince George's County resident in the mid-1960s, he filled Maryland's at-large seat in the House of Representatives before resigning the now defunct statewide post to run for governor in 1966.

He was narrowly defeated in the Democratic primary by maverick George P. Mahoney.

In the aftermath, Spiro T. Agnew was elected governor as liberal-minded Democrats switched allegiance to vote against the more conservative Mahoney.

The current Sickles campaign -- part nostalgia trip, part crusade by an unabashed liberal -- bears very little resemblance to that earlier effort. Most of Sickles' congressional colleagues are now gone and his political base, once centered in Prince George's, has largely evaporated.

Yet, for the man who owns the bragging rights for the continued growth of the Metro transit system, not to mention an impeccable record on labor issues, the campaign is much more than a stroll down memory lane.

With an energy and wit equal to his younger rivals, Sickles is attempting to draw labor leaders, older Montgomery residents and longtime political associates into a coalition to make up in energy what it lacks in money and volunteers.

"I have the drive and desire to do this job," Sickles said at a recent candidates forum.

He also has a keen sense of humor, which he has used to his advantage before several political audiences.

At a February forum, for instance, rival candidate Robert Roosevelt railed at some length against an alleged worldwide network of Italian terrorists.

Sickles, the grandson of an Italian immigrant, said his grandmother would have "turned over in her grave" if she could have heard Roosevelt's pronouncements.

Later, when Roosevelt persisted, to the obvious discomfort of the other candidates, Sickles broke the tension by saying that if his Italian-born mother heard the remarks, she would have said: "Shut up your face."

The audience drowned out Roosevelt with howls of laughter.

Associates of Sickles have said his sense of humor has been the needed lubricant in a host of complicated negotiations on public issues over the years, particularly during the 1970s when Sickles chaired the Washington Metropolitan Area Transit Authority.

First as a member of the Maryland House of Delegates, then in Congress and later as a member of the Metro board, Sickles was instrumental in the formation of the regional transit network and in protecting the interests of Montgomery and Prince George's counties as the system was built.

A Connecticut native who received a law degree from Georgetown University in 1948, Sickles currently is an administrator of union health and pension plans.