Vowing to campaign against one-party rule, Arlington Republicans yesterday endorsed three candidates in the county board and sheriff's races.

Dorothy T. Grotos, a former member of the county board, and Jane Bartlett, a civic activist and member of the Planning Commission, were endorsed for two seats on the county board.

They will face county board Chairman Albert C. Eisenberg and William T. Newman, a South Arlington attorney and Planning Commission member, in the Nov. 3 election.

The candidates run countywide, and the top two vote-getters win.

Ronald B. Hager, a former Arlington chief deputy sheriff, received the Republican endorsement for sheriff. Hager will run against incumbent James A. Gondles Jr.

About 180 people voted in the party canvass at the George Mason University law school.

None of the candidates was opposed for the party endorsement.

The Republicans will not field candidates for county treasurer or commonwealth's attorney.

Those posts are held by Democrats who are running for reelection.

Bartlett said she and Grotos have discussed running a joint campaign for the county board.

"We're going to be doing a lot of things together through the party," Bartlett said. "We've started to set up some joint objectives."

Bartlett and Grotos have said a major theme of their campaigns will be the need for two-party government.

Democrats dominate the county board 4 to 1. The Republican, Michael E. Brunner, is not seeking reelection this fall.

"A one-party system tends to be ingrown and self-serving," said Grotos, who served on the board between 1976 and 1983.

"If everyone is of only one {party}, it's going to be hard to get an issue thoroughly discussed. A lot of our citizens feel left out."

Grotos and Bartlett have been critical of what they say is unnecessary growth in the county bureaucracy at a time when the population of the county has not grown.

Both have said they favor strong protections for residential neighborhoods facing encroachment from commercial development.

They differ on ways to preserve inexpensive housing, one of the major issues now facing the county.

Bartlett called "constructive" the current county efforts to help buy part of the Lee Gardens apartment complex from a developer to set it aside for low- and moderate-income tenants.

The complex is being renovated, a process expected to displace thousands of mostly Hispanic residents.

Grotos said she favors a voucher system to help low-income people afford regular rents rather than the proposal for purchasing units at Lee Gardens for subsidized housing.

"Instead of condemning these developers that are coming in and buying up places like Lee Gardens, we should be thanking them for buying them and renovating them and bringing it up to code," she told a gathering of the Optimists Club two weeks ago.

Grotos told the Optimists that the board's plan could make the area "like a public housing project."

Such efforts would "continue to try to turn Arlington County into the District of Columbia," she said.

Asked yesterday about the remarks, Grotos said her comments "had nothing to do with race or sex or anything like that" but were intended to refer to the domination of Democrats in District government.

Hager, 33, said one of his major themes is that he would be a "full-time" sheriff.

Hager claims that Gondles spent about one-third of his time last year on out-of-town trips. Gondles has said the trips were all for work-related conferences.

Also, Hager said that there has been little public review of a $15 million jail expansion plan and that requirements for the post of part-time deputy sheriff are too lax. Gondles has denied both charges.

Republican leaders hope that yesterday's canvass will represent a change of fortune.

In last year's county board race, the party did not even field a candidate.

"This year we have two," said Scott McGeary, Arlington party chairman.

The party in recent years has been wracked by squabbling between moderates and conservatives.

"We have certainly worked very hard in the past year to rejuvenate the party," said McGeary, who represents the moderate wing of the party.