They're marching in Washington again. It's for the Equal Rights Amendment, a cause that's beginning to show the liver spots of age. Marching for the ERA in the summer of 1978 is approximately as inspirational as taking part in an American Legion parade.

Even people who are for this harmless addition to the fundamental charter certifying the fullness of citizenship for women have developed a cranky attitude about it. The damn thing is like a backward child. It isn't that you don't love it, but it's exasperating to watch it take so long.

The various factions supporting ERA have weakened its popularity. They made it stand for a word like libber, and libber has come to be synonymous with homewrecker, the bra burner who comes in the night to destroy mother love and French chic, the connubial couch. In the nearly seven years since Congress passed the amendment and sent it along to the states to ratify, public understanding of it has diminished.

Won't it permit Methodist ministers to yoke homosexuals in holy matrimony? You can guess what the enemy will do in interrogation time to the Las Vegas chorus girls conscripted into the infantry under this hedonist and hideous amendment.

An amazing descent for an amendment which looked like an innocuous sure shot at the beginning of the decade. It has picked up too many political barnacles to maintain speed and momentum. For this is not a moment when most of us get papillae erectae at the thougth of a liberated woman or a liberated anything else that ERA has come to represent. Liberation is a went, spent word, an irritation at a time when everything is too tight and unfunny for extravagance.

It's a heavy burden fo any piece of legislation to be linked to both Sodom and Gomorrah, to both homosexuality and baby killing. In the last couple of years the ERA people have tried to stay away from such controversies, but earlier women's leadership didn't make it hard to disassociate from them.

As an issue, gay rights flickers and goes out. Laughless and humorously without joy as we may momentarily be, the prospect of the gays stealing our children is only fitfully entertained even by the evangelicals. Anti-abortionism, on the other hand, is pertinacious.

It also speaks the poetry of the hour. Liberty, liberation, equal rights to have the freedom to kill the child within you, free spending, free sex - don't you know there is no such thing as a free lunch? Sooner or later you must pay with inflation or with a nice, big bouncing badge of baby shame.

Against this kind of political and cultural free associating, the pro-ERA' groups have been helpless. To fight back is to risk losing the anti-abortionist support they do have, and besides what are they to say? Today's unwanted fetus will be tomorrow's most wanted mugger-murderer?

As a consolation for defeat, the ERA people are reminded that the courts as well as Congress and many state legislatures are enforcing ERA even without its passage. Defeat, then, is only symbolic.

But symbols are important. They stand for real things as often as not. What are women to think of this symbolic rejection coinciding in time with predictions for an economic turndown? Women, of course, have left home for outside jobs before, although never in such numbers as now, and the same women have gone back home when the men returned from war or the economy slowed. This time, however, tens of millions of women don't have homes except what they provide themselves. This time they have no place of dependency to go back to.

For them, this rejection is no insubstantial symbol, but the threat that if hard times do come they'll be a hell of a lot harder on them than on themen.