AND ON THE THIRD DAY, there was a third governor -- Harry Roe Hughes -- who spoke from a high plane to the people of Maryland, promising them something irresistible if quite foreign: "The highest standard of ethical conduct will begin with the governor and permeate throughout thestate service." We're glad that's settled. Now the new administration can get on to other things. In fact, the heady tone of Gov. Hughes in his inaugural ran true to a new form -- a form used these days by many promising figures taking office, not the least of whom assumed the presidency two years ago.

Perhaps that is why, with all due respect, one may wonder just a little when the new governor (who likes to refer to himself as a "country boy" and who just down-homed the name of the Governor's Mansion to "Grovement House") announces the arrival of a new era in which he will be "vigilant and vigorous in exercising my constitutional authority to see that the corrupt are prosecuted and questionable practices immediately terminated." Surely, this is music to the ears of Marylanders, even if it is an old song; and never mind how many other politicians have found it necessary, for one reason or another, to change the tune later.

How can you knock a promise that appointments "will be based on professional competence and a common commitment to change"? And it doesn't hurt to be told that "experience will be valued, but so will vision, initiative and altruism." But then we come to the new governor's announcement that "there will be no empire-building nor territorial battles." Now that's taking this clean air act just a bit far -- assuming he can decree an end to a fundamental and a age-old impulse of politics and bureaucracy. Surely the point is that Gov. Hughes will try to channel that impulse into useful results during his term of office -- or give it a knock on the head when it gets out of control. We believe that's what the voters elected him for -- and wish him well.