Everyone knows you can't have two winners in one election, so why are Luke Ravenstahl and Mark DeSantis both crowing about victories?

Pittsburgh's Democratic mayor, with 63 percent of Tuesday's vote, has the math on his side and will get to serve the remaining two years of Bob O'Connor's term. He says he's learned some lessons in the last year, and we hope they'll make him a more responsible, more boldly thinking leader.

Mr. DeSantis, the Republican upstart, came too late to the race (skipping the primary), had too few funds (despite raising several hundred thousand dollars) and lacked a party organization (the city GOP is comatose). Yet the Post-Gazette endorsed him and 35 percent voted for him because he was an impressive, articulate candidate who made strong points about jobs, business and efficiency being the key to Pittsburgh's future.

His showing was better than any Republican mayoral candidate since 1965, but in a city where Democrats dominate by 5-1, it was not nearly good enough. If the GOP, either through Mr. DeSantis or another candidate, expects to put up better numbers in 2009 it needs to begin the serious job of party building. Otherwise Pittsburgh's next mayoral race will be decided, once again, in the Democratic primary.

Republicans in the broader Allegheny County can't afford to be smug either. Their party offered no candidate for county chief executive, county controller, district attorney, treasurer or five County Council seats. Its winner of an at-large seat is seeing his management of an elderly client's trust fund being investigated by the district attorney. Its loss of a district seat gives Democrats an 11-4 vise grip on council.

The Republicans can't spin their way out of this grim reality. Despite the solid candidacy and credible showing of Mark DeSantis, the GOP is not ready to compete in the city and it's even losing ground in the county.

That's bad news for all Pittsburghers. The two-party system is a potent force around the country for refreshing and renewing government, but here, unfortunately, it's not getting traction.