By Dave Warner

PHILADELPHIA, Nov 2 (Reuters) - An appellate court judge in Pennsylvania has refused to stop the state from advertising its suspended voter identification law, a publicity campaign that critics argued was misleading to voters.

Commonwealth Court Judge Robert Simpson said in a ruling on Thursday that the groups that asked for the advertising to be halted "never offered credible proof" that the state's campaign would be likely to cause disenfranchisement.

Simpson, a Republican in a state that elects its judges, ruled last month that Pennsylvania could not enforce its new voter ID law for the Nov. 6 election.

The state has continued to run ads that carry the slogan "Show It" with the tagline "if you have it" in small print.

The state American Civil Liberties Union and others who oppose the campaign said it was misleading because voters do not have to show identification at the polls next week.

In his order on Thursday, Simpson called the advertising "education efforts."

The ACLU challenged the voter ID law itself, arguing that it discriminates against minorities, who often favor Democratic candidates. Supporters of the law, which was passed in March by the state's Republican-led legislature without a single Democratic vote, said it would prevent voter fraud.

Thirty U.S. states have some form of voter ID laws that will be in effect for the general election on Tuesday, according to the National Conference of State Legislatures.

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