THE past 20 years have seen few changes in Cambridge politics. Although politicians have come and gone, the basic makeup of the City Council has remained exactly the same since the mid-1970s.

This year, however, the situation is different. For the first time since 1961, three of the council's nine members have decided not to seek re-election. As a result, the council race is wide open. In 1989, more than any other year in recent memory, your vote will make a difference.

As they have been for several years, rent control and development are the litmus test issues for candidates seeking election to the council.

While the system of rent control used in Cambridge is in many ways inadequate, it has managed to preserve 17,000 units of housing for low-and moderate-income city residents. Although critics of the system love to depict it as riddled with abuses, most of the available data on the subject indicates that rent-controlled housing generally does go to the people who need it.

If a majority of anti-rent control candidates comes to power this year, it is doubtful that the system will continue. If it does survive, it will certainly be whittled down in a way that will benefit big landowners and hurt tenants.

SINCE the mid 1970s, Cambridge has pursued a policy of aggressively seeking new development to raise tax revenue. In many ways, the policy has been a successful one. By attracting wealthy developers, Cambridge has been able to tranform itself from a dying industrial center to one of the area's most financially secure cities.

Unfortunately, development has had many negative impacts on the city as well. City residents feel the costs of new construction in terms of increased traffic and polution. And as the city allows the creation of more and bigger office buildings and shopping malls, homeowners and tenants alike are driven out of town.

New development is clearly important to the city. But it is equally important that development be controlled. The city needs to insure that builders give something back to the city, and that every new square foot of office space is balanced by the creation of more affordable housing.

All three of the outgoing council members--Saundra Graham, David E. Sullivan and Alfred E. Vellucci--have been key backers of a progressive agenda for the city. Their loss will be keenly felt during the next two years, unless voters replace them with an equally vigilant team of pro-tenant council members committed to limiting development.

SEVERAL of the 28 candidates in this years election have professed support for these issues. They include the 11 candidates backed by the Cambridge Civic Association: Edward N. Cyr, Francis H. Duehay '55, Esther M. Hanig, Regina Jones, Rena H. Leib, Jonathan S. Myers, Kenneth E. Reeves '72, Renae D. Scott, E. Denise Simmons, John T. St. George and Alice K. Wolf.

Several other candidates are not endorsed by the CCA, but have expressed strong positions in favor of rent control. Among these candidates, James M. Greene, Paul J. Johnson Jr., and Timothy J. Toomey, Jr. deserve serious consideration.

Under Cambridge's system of proportional representation, it is important to vote for several candidates. In the late stages of the vote count, third, fourth and lower-choice votes can mean the difference between victory and defeat for a candidate. We strongly urge you to vote for all of these candidates.

However, the number-one vote is of particular importance. A candidate who does not receive a strong base of first-choice votes tomorrow will likely be out of the running; no amount of tranfer votes will make up the difference.

And of all the candidates seeking office tomorrow, the two who most deserve your votes are incumbents Francis H. Duehay '55 and Alice K. Wolf.

LIKE all of the CCA candidates, Wolf and Duehay have been strong supporters of rent control during their terms on the council. They have consistently voted against a variety of anti-rent control measures--including Proposition 1-2-3.