The law givers of the District of Columbia were on Leon Spinks' side but he preferred a family celebration of his 25th birthday yesterday and remained in Hilton Head Island, S.C.

The D.C. City Council went through with "Leon Spinks Day" and while in session passed a resolution that noted he "deserves the recognition . . . for his struggles, achievements and successes, but particularly for his victory over the self-fulfilling prophecies of this country's urban ghettos."

A big part of that "victory" was his upset of Muhammad Ali for the world heavyweight boxing championship, which he will defend against the former titleholder on Sept. 15, in New Orleans.

Sen. Thomas Francis Eagleton, from Spinks' home state of Missouri, issued a memorandum for the occasion.

Trainer Sam Solomon came here from Spinks' informal training camp to accept the honor for the champion and explained that Spinks had arranged the birthday party in Hilton Head Island before the ceremony here was scheduled.

Solomon was asked if Ali would be harder or easier for Spinks in their next fight.

"Ali can't be any better," Solomon said. "He was in shape the last time. He went 15 hard rounds. He took a battering for 15 rounds; you don't do that out of shape.

"Everybody is making excuses for Ali, but Ali didn't make any for himself after the bout. People don't want to give Leon credit. The trouble is, Leon can read better than Ali - you should see him read the legal langauge in his contracts - but he can't talk as well as Ali - yet. He will."

It was mentioned that Ali appeared to have Spinks in trouble in the 10th round of their last bout, but did not have the energy, the reflexes or the steam in his punches to dispose of Spinks.

"They were outsiders who thought Ali had Leon set up in the 10th round to finish him off," Solomon said.

"But Ali knew he didn't have Spinks set up and Leon knew it. Ali knew it better than anyone else."

Then Solomon made a remark that figures to further bruise Ali's ego: "The fact was, Leon was on orders to coast in the ninth, 10th and 11th rounds.

Was Solomon saying that Ali is shot?

"He's an old man (36) in the boxing game."

How would Spinks, the World Boxing Association titleholder, do against unbeaten Larry Holmes, the World Boxing Council champion?

"Leon can beat anybody in the world . . . anybody."

Solomon said of Spinks' managerial complications and brushes with police, "Leon didn't have a 'problem.' He just wanted to enjoy himself. Nobody wants to let him enjoy himself. Didn't he earn it?"

The trainer noted that after twice being given tickets for not having a driver's license, Spinks had gotten one in Michigan.

York Van Nixon, chairman of the D.C. Boxing Commission, was disappointed that Spinks did not come here because, he said, the Redskins may have boxing exhibitions before preseason games and it would be ideal ot have Spinks come here from the formal training camp is he going to set up in Hammonton, N.J.

Bobby Mitchell, a member of the boxing commission and administrative assistant to Redskin President Edward Bennett Williams, said, "Ed Williams and I are big boxing fans. This is something we have on our minds, but we haven't discussed it for formally yet. If we could get Spinks, it could happen."