How can you tell which party is dominant in our politics? Simple. The dominant party is the one that best embodies and reflects those two most enduring and exceptional of American characteristics -- our determined optimism and belief in change. That political party from 1932 to nearly 1980 was certainly for most Americans the Democrats. But about 10 years ago that all changed. Democrats began defending the status quo and disbursing doubt.

Thanks largely to the leadership of one man, the Republicans became for a lot of people the party of change and optimism. That man was Rep. Jack Kemp (R-N.Y.), who, we now know, will not be elected president of the United States in 1988. But before he formally leaves the fray, Kemp deserves a farewell salute, not only for what he has done but also for what he has tried to do.

Kemp has now learned painfully a hard maxim of national politics: for any candidate in serious pursuit of a presidential nomination, there are only two places you can finish in any primary -- First Place and No Place. The Olympics remains our only televised competition in which a contender can win a third place. In U.S. politics, finishing third gets no bronze medal, but it does guarantee tomorrow's oblivion as a public nonperson unattended by microphones and minicams.

During that earlier era of Democratic dominance, our nation became the most powerful and most prosperous in human history. Then, the minority Republicans were the "can't-do" party, regularly prescribing cold showers and root-canal work for working Americans. Heading into the 1980 campaign, Ronald Reagan was a certified personal optimist without a defined public program. And that is exactly what Kemp, with his patented solution of economic growth through tax cuts, gave the Gipper and the GOP. In a major way, Kemp was both the architect and the engineer of the Reagan revolution.

An energetic rebel with a cause, Kemp in 1988 has been a candidate without a constituency. After eight years of Reagan, Republican voters are roughly split into three unequal parts. First there are those Republicans who are generally satisfied with the administration and therefore lean toward Vice President Bush. Then there are the Republicans who, while not displeased, are anxious about the huge federal deficits and who prefer Sen. Bob Dole. Finally there are the voters who care deeply about moral matters such as abortion and pornography and who, disappointed with Reagan's record on these issues, have committed to Pat Robertson.

Instead of logically trying to secure a generational base of Kemp's own among younger, more optimistic voters under the age of 45, his campaign mainly tried to compete for the party's right wing. The futility of that effort was bluntly explained by one of Kemp's closest conservative friends and staunchest supporters in the House: "Since Taft, the conservative movement has been fueled and sustained by rage and resentment. Jack's problem is that he harbors no resentment."

Resentment is a nicer word for hate. And Jack Kemp is no hater. To him, those on the other side of an issue or the aisle are opponents or adversaries, not the enemy. Much of the right wing runs on paranoia and loathing. (How else to explain that crowd's public exhilaration at the prospective candidacy of the political merchant of venom, Patrick Buchanan?) Kemp, who sincerely seeks an inclusive Republican Party, has stood for civil rights and workers' right to bargain collectively, two items not historically prominent on the agenda of the right.

While his 1988 campaign is a loser, Kemp himself is a big winner on the Maeder political test, named after its inventor Virginia Democrat Ted Maeder, who has concluded after too many campaigns that a politician's personal integrity counts for a lot more than his public ideology.

The current campaign has featured much discussion of character. Nobody is here arguing that Kemp is any plaster saint. But consider the so-called profamily issues, which are proudly championed by political men whose private conduct does not match their public posturing. Last fall, Kemp was a more devoted father than a determined candidate. On all but two weekends, he came home from the campaign trail to see his son, Jimmy, play football for Winston Churchill High School. You can be sure that Jimmy Kemp will remember his father making that effort and that choice. By contrast, Michael Reagan, whose father would become president, was an all-state high school quarterback who never had that thrill of playing in front of his dad.

What is true of sports is also true of political campaigns: they don't build character, but they do reveal it. Jack Kemp has made a difference, and he has made some history. Along the way he has also made more than a few admirers on the press bus.