Arlington Democrats will select a County Board nominee and county Republicans will elect a new party chairman at separate sessions in the next five days.

The Republicans have scheduled a canvass, a version of a local primary, to run from 10 a.m. to 2 p.m. Saturday at the George Mason University Law School at Fairfax Drive and Kirkwood Road, across from the Virginia Square Metro stop.

Candidates for the chairmanship of the Arlington Republican Committee are Scott McGeary, a longtime party activist and current legal counsel and secretary to the committee, and Thomas W. Dennison, a committee member who has been an outspoken critic of the party's current conservative leadership.

McGeary is heavily favored in the contest to succeed Helen Blackwell, who is not seeking reelection.

The Democrats have scheduled a mass meeting for May 13 at which they are expected to nominate Mary Margaret Whipple, the board's current chairman, for a second four-year term. The meeting is set for 8 p.m. at the Lyon Park Community Center at 414 N. Fillmore St.

County Republicans are not fielding a candidate against the popular Whipple, who is expected to run uncontested in the Nov. 4 election.

Whipple will, however, face opposition from Thomas Hall, a former president of the Arlingtonians for a Better County, a self-described nonpartisan political group that endorses candidates in County Board races only. Its convention is scheduled for May 20 at 8 p.m. at Washington-Lee High School's Little Theater auditorium.

Many of ABC's members, including Hall, are federal employes barred by the Hatch Act from participating in party politics. The group has a long history of having endorsed Democrats who ran as independents. But in recent years, County Board candidates have increasingly opted to run as Democratic nominees. Three of the four board members who compose the board's "Democratic" majority ran as party nominees.

Although the ABC has always endorsed the Democratic nominees, many of its members have said they are frustrated by their inability to work in the local campaigns.

Hall said that, for such reasons, he will challenge Whipple for the ABC endorsement as a "matter of principle." He said he wants to offer ABC members the option of endorsing a candidate who will run as an independent, but describes his candidacy as "quixotic."