Yes, Walter F. Mondale can go fishing for a little while. But the Democratic nominee for president had better hit the campaign trail fast, warns the party's highest officeholder, House Speaker Thomas P. (Tip) O'Neill Jr.
In an upbeat mood, the shirt-sleeved Massachusetts lawmaker relaxed in a convention hotel suite and proclaimed to a gathering of reporters that despite all of the polls showing President Reagan's popularity, ''this is going to be a great year for Democrats.''
But he admonished Fritz Mondale not to make the mistake of letting down on the attack as he did during the primary season.
''He's got to go on the offensive all the way,'' said O'Neill, who added that he has already ''had a couple of good conversations'' with former Vice-President Mondale.
''It's just like a football game,'' the Speaker said. ''You've got momentum going. You've got to keep it moving.''
But the white-maned Speaker who for four years has been the chief adversary of Reagan policies saw not the man Mondale, but opposition to the President as galvanizing his party. ''The unification's there for Mondale,'' he said, ''because he's the agent who wants to defeat the evil that's in the White House.''
The biggest problem facing Democrats, he said, is how to woo the young and affluent baby-boomers who flocked to the candidacy of Sen. Gary Hart but who fail to feel the attachment to the party.
These young people, nicknamed Yuppies for ''young urban professionals,'' are those whose ''parents made it to affluency'' chiefly because of Democratic programs like veterans benefits and student aid and fair labor laws, O'Neill said.
''There's a group in America who never appreciated what it was like 40 or 50 years ago,'' he said, arguing that when he started in politics half the population was living in poverty. He said the new generation, unaware of the hard times, is far less concerned about the government support system constructed by the Democratic Party.
''The issue of fairness is the biggest issue you've got out there,'' said the unabashed New Deal liberal, who holds that there is a ''tremendous softness'' in the Reagan campaign, despite the President's personal popularity, because of his cuts in social programs as well as his foreign policy stance.
''There's no question in my mind that it's going to be as tight as your fist, '' O'Neill predicted of the election.
But he also conceded that the Mondale campaign had been in need of a spark, which has now been provided by Rep. Geraldine A. Ferraro as the vice-presidential candidate.
And the House Speaker all but took credit for the selection.
''I told (Mondale) that the time had come for a woman,'' he said. ''You know , everything in politics is timing.''
He added that he had urged the choice of Ms. Ferraro in private and then followed up by going public with his endorsement.
When a reporter pointed out that Ms. Ferraro was only one of several women in the limelight until he endorsed her, he said with a grin, ''Don't you think I know that?''
He recalled meeting the congresswoman six years ago when she was first running for the House and was having trouble from her own party establishment in her Queens, N.Y., district. O'Neill said the retiring Democrat told him she couldn't win because ''it was an Archie Bunker district.''
O'Neill traveled to New York to try to heal the breach. He recalled, ''The minute I met her, I said, 'Boy, this is some lady.' ''
Although he hestitated to offer advice for her in ''womanly'' matters on the campaign trail, the Speaker found no difficulty with stressing her family life:
''Ferraro is a woman. Ferraro is a mother of three children. We've never had a candidate ... who made student lunches for their kids 10 years ago and now is running for vice-president of the United States.''
As for the party's presidential nominee, O'Neill blamed the press for portraying him as an unexciting speaker. ''I'm waiting for the debates,'' he said. ''Mondale's got more brains in one finger than the President has in his whole head.''
Mondale has the talent and ability, according to the Massachusetts lawmaker. ''All he's got to do is use them.''
O'Neill said he was undisturbed by a fear expressed by some Democratic officeholders in interviews here that Mondale is wrapped too tightly in the interest groups of his party. Those views come from Democrats who ''overestimate'' the Reagan mystique, the speaker charged.