It's the political potshot season again - and target No. 1 has become Walter F. Mondale. The stronger Mr. Mondale gets in his run for the Democratic presidential nomination, the more intense the fire from his fellow candidates.
The Republicans are rubbing their hands with pleasure and are already looking forward to the time when they can replay this Democratic criticism of Mondale.
Sniping at Mondale so far hasn't paid many political dividends. Two of the sharpest critics, John Glenn and Ernest Hollings, were among the weakest finishers in this week's Iowa caucuses. But that has not muted them.
The criticism started to get serious two or three months ago and has steadily grown sharper. A few examples from the campaign trail:
On budget deficits: ''Mondale never balanced anybody's budget,'' Senator Hollings says. ''If we have a $200 billion deficit with Reagan, what do you think we'll get under Mondale? It'll be $400 billion.''
On defense policy: Do you think the President is spending too much for defense? Well, he is, Senator Glenn says. But Mondale goes too far the other way , and has shown ''a fundamental lack of support for an adequate defense. . . . Fritz Mondale likes to say he's for a strong defense, but when his vote was needed, his support was weak.''
On leadership: Mondale fails a basic test of leadership by being too cautious , charges Gary Hart. ''The pattern is always there - caution until consensus forms.'' That's why it took Mondale ''18 days before having anything to say about the invasion of Grenada,'' Mr. Hart says.
This is rough stuff. And it could come back to trouble Mondale at the hands of President Reagan - who can simply quote the words of Mondale's own fellow Democrats.
Already this week, the President has alluded to the politics of ''special interests.'' That was a reference, according to GOP officials, to another criticism of Mondale - that he is too closely tied to big labor unions.
A ranking Republican official says the party is keeping close tabs on the Democratic infighting, especially those criticisms that point to Mondale's ''serious flaws.''
President Reagan is fully aware of the damage that can come to a candidate from rhetoric within his own party. It was the man who is now vice-president, George Bush, who coined the phrase ''voodoo economics'' to describe Reagan's campaign promises on the economy. That phrase was resurrected with glee by the Democrats in the general election campaign. Even now, three years later, it continues to surface.
Democrats seem even more inclined to flail away at one another, only to have it come back to trouble them later. It was the mean-spirited struggle between President Carter and Sen. Edward M. Kennedy for the Democratic nomination in 1980 that some Carter aides blamed for his huge loss to Reagan later that year.
The Democratic criticisms of Mondale fall into several broad categories, any one of which the GOP expects to find useful. Here's a brief look at each area:
1. Mondale cannot be elected. This charge has been made repeatedly since the campaign began. It is a favorite of Senator Hollings.
''I really think Mondale can't win'' against Reagan, Hollings says. This charge had its inception, in part, in the polls, where Mondale showed up weaker than Glenn in trial heats against the President. But it's especially strong among those who worry that Mondale will be seen as a throwback to ''discredited'' Democratic policies that led to high inflation and recession.
2. Mondale will be linked to Jimmy Carter. ''If Walter Mondale is the Democratic nominee, we'll hear Carter, Carter, Carter all year long from Ronald Reagan,'' says Alan Cranston. The senator and others say it would be tossing away an important opportunity just to ''rerun'' the 1980 campaign.
3. Mondale and the big spending image. ''Mondale has just promised everything to everybody, with no thought of how it's going to be paid for,'' Glenn charges. ''What I'm saying is, are we going to break promises, or break the bank?''
4. Mondale and the bosses. Glenn, Jesse Jackson, and others have teamed up on this one. Glenn charges that the ''kingmakers,'' meaning the AFL-CIO, have tapped Mondale as their choice, and the American public won't like it. Mr. Jackson carries the argument further - charging that the Democratic Party leadership has rewritten the rules to make it harder for ''long shot'' candidates such as himself to compete in 1984.
5. ''Cautious'' leadership. This is Senator Hart's favorite theme. He chides Mondale for faint-hearted leadership on important issues like Lebanon. Mr. Cranston makes similar charges. Says Hart: ''If Thomas Jefferson had dared to be cautious, the people of this country would probably still be speaking Iroquois.''
6. Mondale and consumers. The former vice-president has been most sharply criticized by Reubin Askew for his support of domestic-content legislation. This proposal would require that imported cars contain a certain percentage of American parts.
Mr. Askew, a former trade negotiator under President Carter, charges that this would put the Democratic Party on the side of a law that would boost the average price of a new automobile to American buyers by more than $1,000.
All this criticism worries at least one candidate, George McGovern. A few days ago he warned that it's all ''hurting our party's chances of defeating President Reagan in November.''