Portland may be more the exception among existing M.L.S. teams. D.C. United and New England, two charter clubs, have stumbled on the field and at the gate, while playing in large N.F.L.-size stadiums with little atmosphere. The Red Bulls, despite their new 25,000-seat arena in Harrison, N.J., have never won a league title and are often starved for attention. More broadly, M.L.S. lacks the rivalries needed to spark fan interest, either because the league is still relatively young or because the distances between cities is too great.

The Timbers’ move up to the top level of soccer in North America in Portland, the self-proclaimed Soccer City U.S.A., suggests that the league may have found the right formula. The Timbers have built on a rich history dating to the North American Soccer League. (Pelé played his last official pro game in Portland, the 1977 N.A.S.L. title game.) After the league folded in the mid-’80s, the Timbers drifted in and out of existence before re-emerging in 2001 as part of the United Soccer Leagues.

The team performed well and captured the imaginations of a small but hearty group of fans known as the Timbers Army that seems to revel in its love of a game and a city that have been largely defined by their outsider status. One Timbers Army fight song (sung to the tune of “You Are My Sunshine”) includes the lyrics “We are mental and we are green, we are the greatest football supporters that the world has ever seen.”

“We have a counterculture sense in Portland, and the Timbers Army made it more participatory,” said Dave Hoyt, the president of 107ist, a foundation associated with the group that has sold 10,000 of their custom-made team scarves, with the proceeds going to charity. “There’s a hunger to feel part of the community.”

Mr. Paulson seized on that sentiment when he purchased the rights to the team, although as wealthy outsiders in a left-leaning and sometimes insular city, the Paulsons were bound to raise eyebrows. While soccer fans applauded their efforts to win an M.L.S. team, for which the Paulsons paid a reported $35 million expansion fee, baseball fans felt snubbed when the Beavers were tossed out of their home so the Timbers could have a soccer stadium. After a fitful search for a new home, the Paulsons sold the Beavers, who were moved to Arizona.