PICKING over the bones of last week's primary elections, both Republicans and Democrats should find some things to prize. Tolerance among voters for the traditional party spectrums appears very much alive.
For Republicans, the California primary for the US Senate was the key test. A moderate, Rep. Ed Zschau, won the GOP nomination in a contest where sharply conservative candidates might have been expected to shine. Zschau's congressional voting record shows him to be a fiscal conservative who is progressive on social and foreign policy issues.
Democrats, too, seem to be resisting the conventional wisdom that they must draw new strength exclusively from the conservative side of the spectrum. In this year's Senate races many of the Democratic candidates showing the most vitality are from the liberal/progressive side of center -- Terry Sanford in North Carolina, Harriett Woods in Missouri, Tim Wirth in Colorado, and Barbara Mikulski and Michael Barnes in Maryland.
This progressive Senate trend, after the Democrats' loss of key liberal seats in 1980, was already discernible two years ago. All five of the Democrats newly elected to the Senate in 1984 were in the progressive mode -- Tom Harkin in Iowa, Paul Simon in Illinois, Albert Gore in Tennessee, John Kerry in Massachusetts, and Jay Rockefeller in West Virginia.
Whatever the prospects of the newest crop of Senate contenders, their presence perpetuates the traditional tension -- in both parties -- between the progressive and conservative wings.
The American system is not only a two-party system. It is a system with diversity in both parties. Ideological tension is essential to a balanced political debate, and to both parties' relevance and competitiveness.
The election cycles starting now for 1986 and '88 give voters a chance to focus on candidates' qualifications rather than any broad ideological trends.
This fall's races are not dominated by any deep dissatisfactions or national issues. There are pockets of economic trouble, as in the farm belt and the energy states. But for most of the country, prosperity continues for its fourth year.
President Reagan's tenure has changed things. Since the recession a few years ago, times have been good. If nothing untoward occurs in the economy or in foreign affairs, the voting-booth question in 1986 and '88 will be chiefly whether this candidate or that is better able to handle the next phase of national affairs.
It will be widely thought that under Mr. Reagan the United States recovered the vibrancy it had lost in a long decline that bottomed during the tenure of Jimmy Carter. Reagan himself will not be a drag on Republican tickets, GOP strategists say; neither will he be a big plus. The attitude is ``We're there and want to keep going,'' says Reagan's longtime campaign spokesman Jim Lake. At the same time, the perception of Reagan's success indicates the public will not go for somebody too far from the center in the next presidential round. Basic issues like war and peace, and social issues like abortion, are not expected to be overriding issues except within certain constituencies.
For candidates, this makes 1986 and 1988 years of opportunity to show what they can do. Prosperity elections usually help incumbents. But an enterprising challenger has a good chance of making it. Zschau, for example, has been waging a smart, energetic campaign that could lead to a close race against Democratic incumbent Alan Cranston in the fall.
For voters, this means a responsibility to follow the campaign closely. Incumbents should not be allowed to hide from meeting their challengers in debate. The public should insist on adequate candidate exposure for insight into how candidates think.