What this country needs is a new set of political hypocrisies. The old one is plain worn out. This is especially true in connection with President Carter's race for renomination and reelection. Right on schedule there seem to have been dredged up all the old familiar circumstances and allegations and high-minded posturings that go with this phase of an American campaign.

We thought it good that Mr. Carter agreed to participate in the proposed three-way "debate" among the Democratic candidates in Des Moines. We thought it prudent and even necessary when he then got out in view of the cataclysmic things happening abroad. But naturally, the president added just a bit of flimflam and excessive self-righteousness to his explanation for not taking part and, just natually and predictably, people who know better began to deplore the president's sound decision as some kind of death blow to constitutional government in our time.

Look -- these forums can be good and useful and revealing. But they certainly do not represent an absolute value or virtue before which all else must fall. Mr. Carter just now is at a critical point in the conduct of a newly changing presidency that must face up to direct and immediate dangers that can't be deferred or toyed with. He needs to weigh what he says for its potential impact abroad. There is more than just ordinary sanctimony to the claim that even while running he must attempt to preserve a modicum of a political national unity and support for his actions overseas. That there is political and imagery advantage to him from this condition is indisputable. But there are also perhaps balancing if not overwhelming disadvantages. Witness the farm-vote risk in the embargo of grain sales.

We would put in the same category of unconvincing outraged innocence the dire charge that the president has been telephoning up a storm from the White House to Iowa despite his solemn claim that he must eschew grubby politics. So what? Every four years the country goes through this ritual tin-pot argument committing politcs while in the office and by means of the office -- remember the concern over Roger Morton's White House office space, for example -- what real political issues and questions were being evaded because of this and comparable fixations, and this year at least the answer is plain.

The fact is a kind of massive geological shift in the elements that make up the world of presidential politics has occured over the past couple of months. New tests and standards are emerging that will have more to do with who gets the presidency than any of this petty complaint about (equally petty) pettifoggery. Malaise and cardigan sweaters and "you said in 1977 once that . . . but you changed your mind" -- all that is over. People, governments and popular and political forces in Central Asia and elsewhere have handed Jimmy Carter a truly serious presidency, one with no escape from high risk, high tension acts that have nothing to do with rabbits and canoes.

Sen. Baker the other night spoke of a "failed foreign policy" as the source of the current national predicament. That will most surely be a legitimate issue -- perhaps the issue. But the point is that people are now looking at Mr. Carter and his Democratic and Republican competitors and measuring each against a specific new criterion: Which if any looks to be the person you would want leading the country at this moment of our history? Which is up to it? Which is good enough?

The distinction between domestic and foreign issues in our politics has never been particularly plausible or authentic. The two are not intertwined more than ever: inflation, the energy crisis, federal expenditures to deal with necessities abroad all affect and will be affected by what happens in Iran, Afghanistan and, swinging back, Russia and the Mideast. Post-Vietnam foreign policy -- a real one -- is finally going to have to be fashioned. The Republicans are going to have to move beyond mere reaction. More important, the Democrats are going to have to move beyond the sentimentality and never-agains that have marked the post-Vietnam mindset, and think instead: what now?

That will require a cold and uncluttered appraisal of what is really happening in the world. The good old American people -- bless 'em -- are probably once again out ahead of the politicians and commentators in sensing this and being prepared for the risk and sacrifices it may entail. We are sure that they are looking for a candidate who shows signs of being able to manage the awesome forces now loose in the world -- and that frankly they don't give much of a damn about whether that candidate, if he exists, is using the right stationery or the wrong phone or any of the other trivia that go with our midly larcenous politics in the first place.