House Minority Leader John J. Rhodes yesterday stepped up the Republican attack on President Carter, calling his administration "inept" a "terrible failure" and predicting Carter would wind up a one-term President.

Rhodes' verbal assault came on "Meet the Press" (NBC, WRC), it was a continuation of an effort by Republican leaders to take experimental swings at President Carter to test his vulnerability in the aftermath of the Bert Lance affair.

Last month, for example, Rhodes charged the White House has been marked by "uncertainty and ineptitude, compounded by moral blindness and a lack of understanding of the processes of government."

The Arizona Republican sharpened that criticism yesterday, saying, "I think the administration's performance thus far has been inept.

"Nothing really has been accomplished and one of the reasons it hasn't been accomplished. I think, is because the administration started out not knowing a thing about the government, and apparently proudly so, with the idea that anything that happened prior to Jan. 20 [Carter's inauguration] had to be wrong . . ."

Rhodes added: "I think it [the administration] has been a terrible failure and that the country has had eight months of churning and chaos without any great amount of results!"

To support his contentions, Rhodes cited "the fact that the rating of the President as far as popularity is concerned, and as far as the perception of the people as to how he is doing his job is concerned, are on the way down."

"In fact," said Rhodes, "it looks like he may well be a one-term President; and it this is true, of course, this should cause the people to look at the altenative, and we [Republican] are the alternative."

Rhodes said Republicans in Congress are trying to take advantage of what they see as Carter weak gress are trying to take advantage als on taxes. Social Security and people what they could except" if Republicans were in power.

Indeed, he said, because of Carter's failings. "I do feel it hightly possible that we could take in the House of Representatives enought [new Republican members in 1978] to make a majority," Rhodes cautionsly predicted that his party, could pick up 72 new seats in next year's congressional races.

The latest count shows 289 Democrats, 144 Republicans and two vacancies in the House.

The Arizona congressman suggested that President Carter take advantage of a "lot of smart Democrats in this country" who could tell him "what he should be doing for the rest of his administration."

He acknowledged that Carter had a "smart Democrat" in Bert Lance, the former director of the Office of Management and Budget who resigned Sept. 21 because of an investigation into his financial dealings.