The 19th Legilative District in Montgomery County was once described as having the shape of an elephant on roller skates. Assuming that the average pachyderm is an awkward skater, the description fits in more ways than one.

The Republican Party, the party of the elephant, has led a precarious existence in this Wheaton-based district, a land of postwar subdivisions, commuter traffic jams, shopping centers, apartment complexes, retirement communities and, above all, Democrats.

This is the district that features the only election precinct in the county with more than 2,000 registered Democrats (precinct 13,11 in the Kemp Mill neighborhood). It is the district where nearly three of every four voters register as Democrats. And it is the district where this year the Republicans could not find anyone to run for the state Senate and recruited only two candidates for three delegate seats.

But despite the one-party complexion of the district, it is by no means lacking in the sort of competition that brings politics to life. The Democrats manage to take care of that by themselves. As one longtime precinct chairman put it recently: "If you want to get a quick lesson in why and how the county Democrats beat on each other, take a look at the 19th this year. It's got it all."

On one side of the intra-party legislative fight is a foursome of incumbents with a total of 42 years service in the Maryland General Assembly - Sen. C. Lawrence Wiser and Dels. Lucille Maurer, Helen Koss and Eugene Zander. They are united, organized, well-financed and confident.

On the other side is a coalition of challengers that is nearly the incumbent slate's equal in terms of name recognition and political experience. There is Senate candidate Sidney Kramer, a former president of the County Council and his party's 8th Congressional District candidate in 1974, along with delegate candidates Idamae Garrott, another former council leader who four years ago was the Democratic nominee for county executives; Be Be Bailey, a Wheaton businesswoman and newspaper publisher, and Dennis Cochran, a teacher at Albert Einstein High School.

All of these candidates, with the possible exception of Cochran, have been politically active long enough for most of the voters in Wheaton, Aspen Hill, Kensington, Glenmont and northern Silver Spring to know who they are and what they stand for. Their roots are as deep as the suburban region itself, going back to the 1950s, when split-levels and bungalows were blossoming along the Georgia Avenue corridor at a rate virtually unmatched in the nation.

Because of this, there are many political observers in the district who believe the Sept. 12 primary in the 19th will be decided by old and hardened perceptions rather than the issues of the day, that the candidates will rise or fall on their personalities and traditional buzz-words such as growth and development and rent control.

For the most part, however, the candidates have shown a reluctance this year to bang away at old ideological and personal divisions. Like all other politicians in 1978, they are talking about taxes and waste more than anything else.

There is at least one notable difference between the tax position of the two slates. Wiser and the three incumbent delegates voted for the one-cent sales tax increase the Mandel administration pushed through the legislature in 1977. They argue now that there was no way to know back then that the state would end the year with a revenue surplus and that they feared that aid to counties would be cut without the tax increase.

Kramer and the other challengers, who of course never had to vote on the issue, are telling voters that they would have opposed the sales tax increase.

Hindsight aside, the two slates seem to diverge philosophically on the sales tax. The challengers maintain that the sales tax is the most regressive of all taxes and that it and the property tax should be reduced, with a more progressive state income tax carrying a greater burden in producing revenue for the state.

Wiser, Koss and Zander, in an interview last week, said they would work to make the income tax more progressive (currently, a person earning $3,100 a year pays at the same rate as someone earning $51,000), but they had no complaints about the sales tax and openly feared a much greater reliance on the income tax.

"The sales tax does have an element of progressivity to it," Wiser argued, "because of the food and drug exemptions.With the sales tax, at least you know that the very wealthy are going to have to pay it. Because of loop-holes, that isn't true with the income tax."

Added Del. Koss: "As far as the public is concerned, they don't find the sales tax burdensome. If you dropped the sales tax and tried to raise the same dollars through the income tax, the burden would fall on the middle class."

"There'd be a revolution in Montgomery County, it would be unrealistic," concluded Zander.

Other than this one specific point of dispute, the differences between the two slates seem to have as much to do with form as with substance. Their campaign statements offer all the traditional themes of outsiders versus insiders.

The incumbents emphasize their experience in Annapolis and their work on legislative committees - Maurer and Zander on the House Ways and Means units unit; Koss as chairman of a subcommittee on ethics; Wiser on the administrative review committee.

"We know how the system works in Annapolis," said Wiser. "And frankly, we think we're one of the best teams there. If Sid and Idamae weren't around, I doubt we'd have any opposition."

Kramer and Garrott are around, however, along with Bailey and Cochran, and all four of them are saying that the incumbents have become arrogant, that they have not kept in touch with the district.

"There needs to be communication between Annapolis and Rockville (the county seat)," said Kramer."Idamae and I worked on the council, we know what the problems are. We'd have a clear interest and understanding in the hundreds on local bills the delegation deals with. I've never seen one of the incumbents at a council meeting. They fly by the seat of their pants."