SEN. Bob Packwood's atrocious behavior toward women was the major factor pushing him out of office. But his relations with corporate lobbyists were, in their implications, equally disturbing. The senator's highly detailed diaries portray an intimacy that goes far beyond the needed working relationship between lawmakers and those with an interest in how laws are made. Aside from Mr. Packwood's efforts to ease an alimony burden by getting lobbyists to offer work to his ex-wife, most of this activity might be considered unremarkable in Washington - just everyday business. But outside of the capital, lots of citizens will find their suspicions about sleazy government amply confirmed. Lobbying is an integral part of the democratic system. Legislators have a duty to look out for interests important to constituents. And those interests will often be businesses or labor groups. But when do those voices, amplified by cash for campaign treasure chests, drown out the broader public interest? The Senate has changed its rules to more tightly restrict the gifts members can accept from lobbyists. It has also passed a bill requiring wider disclosure of lobbying activity. The House should follow suit, despite the inclination of its leadership to give lobby reform low priority this year. Both chambers should consider other steps as well, such as making it clear when lobbyist-supplied language is inserted into legislation. But rules changes and new laws aren't enough. The ultimate safeguard against undue coziness with lobbyists is the integrity of individual public servants. Senator Packwood's sad chronicle should be sparking a lot of soul-searching among his colleagues in the Capitol. Rule changes and new laws aren't enough; the ultimate safeguard is individual integrity.