Ask any of the four Republican candidates in Fairfax County's 50th District about their toughest competition in the Sept. 8 House of Delegates primary, and they won't point their fingers at ballot box opponents or simmering political issues.

The real hurdles, they say, are summer vacationers and courtroom red tape.

Four Repuablicans -- George Landrith, Meghan Schreiber, John S. Buckley and John H. Rust Jr. -- are seeking their party's nomination in the newly created 50th District which covers Fairfax County. Under Virginia's new redistricting plan, rejected as unconstitutional Tuesday by a special three-judge federal court in Richmond, the 50th District will have three seats. And the three highest vote-getters in the primary will carry Republican banner in the Nov. 3 general election.

But the court ruled that the winners may serve only one year, instead of the usual two-year terms, and ordered the General Assembly to draw up still another redistricting plan with new election to be held in 1982.

The last-minute court rejection of the redistricting plan isn't the only headache the candidates face. The primary is scheduled for the day after Labor Day, when many voters will be preoccupied with getting children off to school.

"Sometimes I wonder if people even know there's a campaign going on," grumbles Landrith, a personal career consultant making his political debut in the race.

Buckley, one of two incumabents in the 50th District race, says he hasn't even printed his campaign handouts yet, even though the primary is less than two weeks away.

"What if I spent all that money printing material and the courts changed my district?" speculated Buckley, a political consultant, before the court decision was announced.

Two candidates, Buckley and Rust, are seeking their second terms in the General Assembly. The other two, Landrith and Schreiber, have worked in political campaigns for several years but are campaigning for office on their own for the first time.

The Democratic Party didn't muster enough candidates to hold a primary, and the two Democratic nominees -- Dorothy ys. McDairmid and Ken Plum -- automatically will advance top the general election.

To listen to the GOP candidates, few issues have emerged in the campaign. Buckley claims short election period has prevented issues from surfacing.

Rust has another explanation: "There's just not the public focus I found in the last election. The economy was clearly the issue in 1979. Now there is only a muted concern -- people are optimist that what President Reagan is doing will work."

Because of the lack of issues, most political observers say the name recognition of the incumbents should be a boon to Buckley and Rust. That could leave the real primary contest, according to political observers, between Landrith and Schreiber, two relative unknowns outside of political circles.

Despite the added power of name recognition, the two incumbents are planning for the most expensive campaigns. Buckley estimates his total bill for the primary and the general election will be about $30,000. He also plans to use extensive mail-out strategies, orchestrated by nationally known direct-mail wizard Richard Viguerie, whose work was credited with giving Buckley his strong victory inthe 1979 campaign.

Rust, a lawyer and former city attorney for Fairfax City, says he anticipates spending $20,000 for the general election, but doesn't know yet what he will spend on the primary.

Meanwhile, Landrith projects that the two campaigns will cost him at least $15,000. Schreiber, manager and head buyer for a Washington retail store, says she has no projections for her campaign spending.

Although the views of the candidates don't vary significantly on most issues, Buckley and Landrith seem to be concentrating on conservative fiscal and tax issues, while Rust and Schreiber have branched into some social issues.

Two candidates have strayed from the party line on one major issue: the Equal Rights Amendment, which must be ratified in three more state legislature by next June if it is to be added to the U.S. Constitution. It has failed repeatedly in the Virginia General Assembly.

Incumbent Rust, who opposed the ERA during his first election bid, has reversed his position and says he now will mote to support the ERA.

"The courts have been stepping back from issues involving equality, so they are going to have to be addressed legislatively," says Rust.

Schreiber, the only woman in the race, declares: "I'm for ERA -- how could you be against it?"

She adds, however, that if a majority of her constituents indicated opposition to the ERA, she could be convinced to change her vote.

Both Buckley and Landrith express vehement opposition to the ERA. They argue that ratification of the amendment would throw too much power to the courts and the federal bureaucracy as interpreters of the law.

All four candidate follow the Republican conservative route when it comes to government spending, although some aremost strict than others Buckley and Landrith favor a state constitutional amendment that would put a ceilng on state spending, while Rust contends the amendment is unnecessary, that the General Assembly should decide how to appropriate state funds.

Rust and Schreiber, meanwhile, are focusing on the rising crime rate in the suburbs, an issue of growing concern to their constituents, the two candidates say.

"The Virginia state prison system is antiquated and overcrowded," notes Rust. "We need more prison space and more alternatives to prison for for nonviolent criminals."

According to Schreiber, lawmakers should concentrate on strengthening sentencing and parole laws.