Sen. Bob Dole is doing himself no good by his feckless efforts to beat life into a dead horse. George Bush is gaining nothing by demanding that Dole disclose his wealth. What does he have, and when did he get it? This petty sniping makes both Republicans look worse than they are. Come on, guys, knock it off!

The Iran-contra affair long ago ceased to get the public adrenals pumping. Not one person in 10,000 is hungering to learn about the role of Vice President Bush in the fiasco. The president fathered this baby. Bush wasn't even an uncle.

Nevertheless, for reasons that must seem to him tactically sound, Dole keeps harping on a tired theme: What did Bush know and when did he know it? Who gives a damn? Bush has said over and over that he was generally informed of the arms/hostage deal, that he was not kept advised of particulars and that he solidly supported the president's aims.

This may not be enough for Bob Dole and The Des Moines Register, but it is more than enough for voters who long ago got bored with such penetrating questions as, ''Was the meeting of the National Security Council on Jan. 7, 1986, a meeting of the full council?''

Maybe a handful of political junkies still care deeply about the Iran-contra affair. The most savage Reagan-haters still slaver at the prospect of putting Ollie North behind bars. The rest of us accept the lamentable truth that Reagan's road to political hell was paved with his good intentions: he meant to free the hostages, to improve relations with Iran and to prevent the establishment of a Soviet base in Nicaragua. Toward these ends the president and his aides acted boldly but unwisely. The president repeatedly has expressed sorrow for his mistakes. Bush has publicly rued them. If there is political advantage to be gained by chewing on this dry beef, I cannot perceive it. No juice remains.

Negative campaigning rarely succeeds in American politics. To be sure, politics is a body-contact sport. The press, bored by issues, loves nothing so much as let's you and him fight. When the hooks have barbs and the shafts have witty points, the fans whoop and holler.

But a little of this bare-knuckled stuff goes quite a long way. Dole should be especially aware of that truism. In nagging at Bush over the Iran-contra affair, he runs a serious risk of reviving old images of the Dole who loves to cut and slash. By the same token, Bush will get little mileage out of personal attacks on Dole. The senator would be well advised to disclose his assets and get that distasteful business over and done with.

The two leading Republicans, Bush and Dole, have an obligation to move this campaign to a higher level of information and debate. What is most needed is a serious exposition by the candidates of where they would lead the country if they are given the chance.

Social problems have to be addressed. By general agreement, current programs of public welfare are a mess. What would Bush and Dole do about them? Sen. Orrin Hatch of Utah, who's not even a candidate, has dared to propose a conservative approach to the troublesome business of child care. What would Bush and Dole propose? What of the homeless people? Is there a federal obligation here?

It would be constructive to hear the candidates on the plight of public education. One study after another has documented the shortcomings of our schools. Yet education historically has been a primary responsibility of the states and the localities. How do they see a federal role?

Fiscal problems are no less grave. What can be done -- politically and realistically done -- About our imbalance in trade? About federal deficits? About the weakening dollar? Are we spending too much on defense, or not enough? If higher taxes must be imposed, what taxes?

I couldn't care less about where George Bush was on the afternoon of Jan. 7, 1986, or whether Bob Dole has assets of $1 million or $2 million. Let's get to things that matter.