Ira Lechner wasn't an official member of the Virginia delegation, but that didn't stop him from going to Philadelphia. As a Democratic candidate for the U.S. House from Northern Virginia's 10th District, he figured it would do him good to be where the Democrats were--and last weekend that was at the party's midterm conference.

Lindsay G. Dorrier Jr. had never been to a national political convention and until three weeks ago, the 38-year-old commonwealth's attorney from Charlottesville had no plans to go to Philadelphia either. But when he won his party's nomination to run against Republican Rep. J. Kenneth Robinson in the 7th District, Dorrier put the Democrats' gathering on his schedule.

Dorrier and Lechner were among dozens of candidates who streamed through the Philadelphia Civic Centre over the weekend, sporting campaign buttons with names that were lost on everybody but folks from their home states.

But if the local candidates felt like small fish in a big pond, they weren't perturbed. "I got an awful lot accomplished," said Lechner. "I did there in 40 hours what it would have taken me three or four weeks to get done back home."

For Lechner, a former state legislator from Arlington who won a party primary earlier this month, the Philadelphia convention was a chance to touch base with national Democrats, some of whom he hopes will come across the Potomac to campaign for him in the fall.

"Standing in the lobby in front of the main convention hall, I saw virtually everybody I needed to see in national politics in the space of four or five hours," said Lechner. "To call these people on the Hill, arrange a meeting, have the staffs deal with each other--all that is much more difficult."

Lechner didn't just hang out outside the convention hall. He attended two political skills workshops, one on combating the New Right and the other on polling, featuring free advice from pollster Peter Hart ("whom I could never afford," said Lechner). He also addressed a meeting of Young Democrats, trying to interest young politicos in volunteering for his campaign.

And finally, there was the mingling with the PACmen, representatives of the political action committees who have become the overlords of federal elections. By Lechner's count, he met with almost half a dozen--from Friends of the Earth to the Communications Workers to Pamela Harriman's Democrats for the '80s.

Lechner also was able to do some down-home politicking. "I keep running into people from the 10th," Lechner said happily as he churned his way through a crowded party, pointing out reporters, congressional staff members and other Washington-based political people who make their homes in Northern Virginia.

For Dorrier, there was the lure of a dinner for congressional candidates at Bookbinders Restaurant, a chance to meet Democratic National Committee Chairman Charles Manatt and assorted other national figures and to hear the tone and substance of the party's internal debate. "It was important to go for the issues that were debated and for the contacts," said Dorrier.

Missing at the conference was Virginia's Democratic candidate for the U.S. Senate, Lt. Gov. Richard J. Davis, who, according to an aide, remained at home to keep several "scheduled private appointments."

"He had a lot of things to do in Virginia," said aide Robert Watson. "It would have been an interesting experience to go but since he was only nominated three weeks ago, he still has a lot of catching up to do." Davis, the party's top vote-getter last fall, entered the Senate race in early June after the state party spent critical weeks looking for a candidate.

Some of the Democrats at the convention questioned Davis' priorities, noting that the former Portsmouth mayor--behind his Republican opponent, Rep. Paul S. Trible of Newport News, in fund-raising--could use some national exposure and contacts. "I would have come," one party leader said tersely when asked whether it would have helped Virginia Democrats for Davis to appear.

Also missing--not only from Philadelphia but from the political scene--was Del. George Grayson of Williamsburg, the Democrats' nominee in the 1st District congressional race. Grayson, in a curious and abrupt announcement last week, dropped out of the race, citing the physical stress of the campaign.

So far no prominent Democrat has emerged to replace Grayson, leaving Virginia Democrats once again scrambling for a candidate in a race where they had started with at least even odds. And all of this less than a year after the party scored its biggest victory in 16 years with the election of Gov. Charles S. Robb.

Robb, as always cool and collected, took the long view. While expressing disappointment at Grayson's withdrawal, Robb was not discouraged. "Certainly we have had more than our share of what some might construe as unfortunate breaks," said Robb during a brief pause in his hectic schedule in Philadelphia, "but it only tests the strength of the system."