ANY DOUBTS about the genius of the U.S. Congress at self-preservation can be quelled by reviewing what it has quietly done to gut the election reforms of the past decade.

In the last week of their 1979 session, both houses passed "noncontroversial" amendments to the Federal Election Campaign Act that will make it easier for most incumbents to remain in office. (A mere 95 percent of the incumbents who sought reelection in 1978 won.)

One of the amendments' effects will be to render the disclosure provisions of the law all but useless to political opponents, journalists, public interest advocates, voters and other potential troublemakers.

The measure provides that members may submit up to 10 phony names among contributors listed on each campaign finance disclosure report. It's called "salting" in the House Administration Committee report on the bill. The statute uses more formal language: "A political committee may submit 10 pseudonyms on each report filed . . . "

Consider the possible effect. A candidate's committee files nine reports per two-year cycle. If each report contains 10 phony names, and each phony contributor is listed as having given $1,000 (as provided in the Federal Election Commission regulations) that's $90,000 in bogus contributions listed. And a candidate can form as many committees as he wants, meaning that his campaign could have $180,000, $270,000 or more in phony gifts and givers listed.

This year it's likely that some campaigns will disclose more phony contributors than real ones. Look for a great increase in reports of large-scale political giving by pseudonymous nuns and librarians.