MOST PRESIDENTIAL candidates claim the year in which they are running is a turning point in history, a moment of great decision, when the nation's future for a generation or two is at stake. George Bush, announcing his candidacy yesterday in Houston, made no such claims. The crucial election in his view was 1980: "after seven years of hard work, we have" -- is this pun intended? -- "righted ourselves." The economy is now growing again, he says, and we are strong once again abroad. "We don't need radical new directions," he goes on, "we need strong and steady leadership. We don't need to remake society, we just need to remember who we are."

Mr. Bush comes with the huge built-in advantages and disadvantages of the vice-presidency. He used this occasion to say he is stepping out of the shadow of the president in which vice-presidents do and ought to exist and sharing "my own hopes and intentions." But those looking for great policy differences from Mr. Reagan will be disappointed. Mr. Bush wants more spent on college scholarships, and he calls for a taxpayer's bill of rights (whatever that is). He pledges, as Mr. Reagan did in 1984, that "I am not going to raise your taxes, period." He assures us that "I do not hate government." He praises the Reagan record on arms control. He criticizes it on the environment. But he is light on specifics.

What Mr. Bush talked about most was obligation -- the obligation of a mostly affluent population to the less fortunate at home and out in the world. Affluence implies "helping your brothers and sisters, whoever they are, wherever they are, whatever their needs," he says, in words that recall Mario Cuomo's analogy of society as a family. The son of a Wall Street investment banker denounces "greed on Wall Street and graft in city hall." In a country whose cultural tone is increasingly set by the gaudy, glitzy rich, Mr. Bush preaches an ethic of austerity and service that flows from the best traditions of his family and his party. Attacked as a privileged preppy, Mr. Bush recalls the great Yankee achievements -- freeing the slaves, providing universal education, assimilating immigrants. Americans have an obligation to serve others in their communities and, this foreign policy hard-liner adds, in the armed services. America has an obligation to go beyond containment and help "freedom fighters" in Afghanistan, Africa and Nicaragua.

Mr. Bush has raised $12 million and leads in polls, but he faces tough initial contests in Michigan, Iowa and New Hampshire and is regarded with derision by most experts. We did not see in Houston the "tiger unleashed" Mr. Bush promised last weekend, but we saw something more than the acolyte he has often seemed. Mr. Bush has been advised to position himself this way and that; he seems to have decided to present himself much as he is, and make the best of it. He has a campaign "style" problem that distorts rather than reflects the nature of the man. A lot is riding on whether he can overcome it.