That's the question at the heart of Republican Jack E. Robinson's battle to get his name placed back on the September primary ballot for U.S. Senate.

Robinson asked the Supreme Judicial Court Friday to reinstate 129 of his nominating signatures disqualified by Secretary of State William Galvin. The names were dismissed because the backs of some signature sheets were printed upside down.

A lawyer for the state Attorney General's Office, representing Galvin, told the court the signatures should not be reinstated because the printing errors constitute a violation of state law requiring signature sheets be "exact copies."

The attorney general and the Massachusetts Democratic Party are fighting Robinson's appeal of a State Ballot Law Commission ruling which found he was 14 signatures shy of the 10,000 needed. The commission's ruling came after Galvin's decision to reject the 129 signatures.

Assistant Attorney General John Hitt told the court that the sheet of paper should be presented to potential signers right-side up to avoid confusing and misleading voters.

"If the court moves away from exact copy as exact copy, we're on a slippery slope," Hitt said.

When pressed by the five justices, however, Hitt said everything else about the sheet was an exact copy.

"How would any signer be prejudiced or influenced unfairly because the form was upside down?" Justice Judith A. Cowin said.

William McDermott, a lawyer representing Democratic Party Executive Director Mark White, argued Robinson should have filed an appeal as soon as Galvin issued his decision last month.

Robinson also asked the state to toss out the original challenge to his nominating signatures by the Democratic Party. It was that challenge -- combined with the signatures voided by Galvin -- that led to the Ballot Law Commission ruling.

Robinson said the court should overturn the decision because the copy of the challenge sent to him was missing White's signature.

McDermott said the party followed the intent of the law by notifying Robinson of the challenge as quickly as possible.

But Robinson said those trying to force him off the ballot couldn't argue he did not meet the "exact copy" rule because his sheets were upside-down -- only to then argue the rule should not be adhered to in the case of White's signature.

"They can't have it both ways. Either we consider these statutes literally or we don't," he said.

If the court agrees with either of Robinson's arguments -- that the 129 signature should be reinstated or that the Democratic challenge should be rejected -- his name would be placed back on the GOP primary ballot.

Robinson, who said he has spent about $200,000 on the signature battle, represented himself in court. Robinson said he has no staff and will not try to raise campaign funds until a decision is reached.

He said he hasn't "ruled in or out" the possibility of a write-in or sticker campaign.

The court could issue a decision within days.

The state's top Republicans, including Gov. Paul Cellucci, withdrew their support for Robinson after embarrassing details about his past were revealed, including his arrest on a charge of drunken driving -- for which he was eventually cleared -- and the existence of a restraining order taken out against him by a former girlfriend.

If the court rules against Robinson it will mark the first time the Republican Party has failed to field a candidate in a U.S. Senate race in Massachusetts since 1916, the year senators were first elected by popular vote.