It was good to see lawyers for and against the state's voter-ID law agree that the destructive statute should not be imposed for the May 21 primary. That means voters may be asked to produce a photo ID, but even if they don't have one, they will still be able to vote on a machine.

Gov. Corbett signed the law pushed by Republican lawmakers last year to supposedly protect Pennsylvania from the scourge of voter impersonation. But when it had to prove the case in court, the state quickly stipulated it had no proof of hordes of voter imposters. Commonwealth Court Judge Robert Simpson halted enforcement of the law in the general election, but on grounds that the state failed to make it possible for voters to easily obtain IDs before the election.

The Republicans' continued insistence that the law is needed has given credibility to the assertion of Democrats and other critics that the law and 10 others like it in other states were written to undermine the 2012 presidential election. Indeed, House Majority Leader Mike Turzai said as much last year when he predicted the law would help Mitt Romney win the presidential election in November.

Romney didn't win, and the plan backfired in Pennsylvania, where outraged voter advocates fought it tooth and nail as a tool to discourage certain voters. Both the elderly and the young would have the most trouble meeting the law's requirements since they - many of them urban transit users - are more likely to lack the most acceptable form of ID: a driver's license. Other acceptable documentation include non-driving photo IDs and birth certificates, which are difficult for many residents born in another state, or in Puerto Rico, to obtain.

Eventually, the state adjusted its rules and came up with a Department of State photo ID. All a voter has to do is find a Department of Transportation center and present an address, Social Security number, and date of birth to get a free card. But about 80,000 voters still have not done that.

The state has argued that anyone who needs ID could get one form or another. But its assurances that no one will be unduly disenfranchised aren't enough. Besides, the law itself is unnecessary. A system to detect voter impersonation already existed. Under the old rules, voters new to a polling place could be asked to produce identification by a poll worker, and regular, recognized voters must sign in and have their signatures compared by workers.

It's a shame that Pennsylvania hasn't given up on imposing this barrier to voting when other states are trying to make it easier for people to vote. New Jersey, for example, is moving toward an early voting system. It's not enough to postpone implementation of voter ID for the May 21 primary. Commonwealth Court should strike down this law when it hears the full case in July. If it doesn't, the state Supreme Court should, and end this sorry chapter in Pennsylvania history.