Selected Texas driver’s license offices in major metropolitan areas are expanding their days of operation to include four hours on Saturdays, offering potential voters another window to apply for free photo IDs required of voters.The electronic identification certificates are valid for six years and can be used for voter identification only. Nearly 50 offices statewide will be open Saturdays, solely to handle requests for the certificates. They are intended to aid voters who do not yet have a viable form of ID.The extended hours begin today and end Nov. 2. The Texas Department of Public Safety began accepting applications for the documents in late June. As of Sept. 6, only eight had been issued, according to DPS officials. Offering the documents is a requirement of state Senate Bill 14, which mandates that people furnish a photo ID before voting. The Legislature passed the bill in 2011, but it was on hold until a Supreme Court decision this year paved the way for it to take effect. In a statement, DPS officials said most Texans already have what they need to cast ballots. Current law says voters can show a driver’s license or state-issued ID; a passport or pass card; a military ID, a Texas concealed-handgun license or a naturalization or citizenship certificate with an ID. Applicants for the free IDs must furnish proof of citizenship and identity and be registered to vote or register at the DPS office. Opponents and supporters of voter ID have both cited the low number of issued IDs as evidence that their claims are correct.Opponents, including Democratic lawmakers and representatives of minority groups, say that even though the ID is free, the costs to obtain the needed documents are a hurdle for low-income voters, the elderly and minority groups.Republican lawmakers and others say the low number of free IDs issued shows that, as they have argued for years, most Texans already have the identification required to cast a ballot.