ST. PAUL, Min (MNN) -  There could soon be a vote in the Minnesota Senate on a bill that would require voters to present photo ID at the polls before they receive their ballot.  Backers say it will prevent voter fraud with a very basic and commonly-used check of a person's identity.  But opponents say Minnesota does not have a voter fraud problem and the requirement will discourage Minnesotans from voting if they don't have photo ID because they don't need it or can't afford it.  Governor Dayton has not said whether he would veto the bill but has not been very supportive of it either.  But Republicans are also talking about putting the question to voters as a proposed constitutional amendment on the ballot in 2012.  Doing that would bypass any potential veto by the governor.       Legislators in Wisconsin could vote on a similar measure in May.  The Wisconsin Assembly and Senate are still working on different versions of the Photo I-D bill.