When President Reagan accepted the resignation Tuesday of White House chief of staff Howard Baker, the "deep regret" expressed by the chief executive reflects the feelings of many Americans regardless of political affiliation.

Baker demonstrated old-fashioned patriotism and loyalty 15 months ago when he put aside presidential ambitions and a $1 million-a-year law practice in order to help a White House mired in scandal.In that brief period, he certainly proved to be the right man for this difficult job. Authoritative, credible, and well-liked, Baker helped restore stability and respect to a White House shaken by the Iran-Contra scandal. As chief of staff, Baker also helped guide President Reagan through two super-power summits and win ratification of a historic arms reduction treaty.

Though Baker's sudden departure is surprising, the selection of Kenneth Duberstein as his replacement is not. The well-known illnesses of both Baker's wife and mother necessitated frequent absences. During those absences, Duberstein picked up much of the slack.

With his primary mission accomplished, Baker is leaving the White House as the Reagan presidency is winding down. Realistically, few of the administration's major objectives can be achieved in the little time that's left. The limited agenda that remains should be easy to manage.

Meanwhile, give Howard Baker high marks for his shrewd, calming performance as Ronald Reagan's right-hand man. Though Baker would have made a good president himself, he seems destined to have helped another succeed in the presidency. For now at least, his departure rounds out a distinguished political career.