While answering questions from Democratic activists at a Rockville restaurant Monday night, Doug Duncan — the former Montgomery County executive who is running to regain that office — said he’d “always” been a steadfast supporter of the Purple Line.

But that depends on your definition of “always.”

What Duncan (D) didn’t say Monday is that the Purple Line he wanted is quite different from the one now on the books: the 16-mile light rail line inside the Capital Beltway linking Bethesda, Silver Spring and New Carrollton. State officials are seeking private investors for the project, once known as the “Inner Purple Line,” and awaiting completion of a federal environmental review.

During his first campaign for county executive in 1994, Duncan signed a pledge to oppose light rail from Bethesda to Silver Spring, especially if it happened to cross the fairways of the Columbia Country Club or pass through land behind expensive Chevy Chase homes. A copy of the agreement is on the Action Committee for Transit Web site, under the “Purple Line History” tab.

For most of his three terms as executive (1994-2006), Duncan supported an “Outer Purple Line,” a heavy rail project running mostly north of the Beltway, bypassing Bethesda and Silver Spring to connect White Oak, Wheaton and Grosvenor. Duncan said the idea was to bring public transit to future job and population centers while also making it easier to eventually connect to Northern Virginia. It was also at least twice as expensive as the light-rail inner line, now estimated to cost $2.2 billion.

When support for the outer line wasn’t forthcoming, he offered a compromise, devised by Metro officials at his request, that would use Metro trains to carry riders from Medical Center station near the National Institutes of Health, along the Beltway and then south into Silver Spring.

The switch prompted one Inner Purple advocate, then-ACT president Ben Ross, to say at the time: “He’s willing to put the Purple Line anywhere at all, as long as his contributors from the [Columbia] Country Club don’t have to look at it while they play golf.”

Ross, who attended the Monday night event and asked Duncan about his position on the Purple Line, tweeted attention to Duncan’s revision of history the next day.

“He supported the Purple Line, just not the one that could be built,” Ross said.

In early 2003, the County Council voted 7-2 to reaffirm its support for the Inner Purple Line.

Duncan said Wednesday he didn’t think he misled the audience Monday night.

“I’ve always supported the Purple Line. It was a question of alignment,” he said, adding that his concern about the inner route was its impact on the wooded Georgetown Branch Trail.

“But, we had a good debate on it, and the decision was made to put it somewhere else, and I support that decision,” he said. “We’re not going to revisit that. We need to get it built.”