In a moment of extraordinary honesty, a GOP congressman from Wisconsin said a new voter ID law will help the eventual Republican presidential nominee win the state in November.

Rep. Glenn Grothman's prediction, made in response to questions about Tuesday's primaries in the state, gave credence to critics of voter ID laws who say they are tools used by conservatives to disenfranchise the poor and minorities, many of whom vote for Democrats.

Grothman told WTMJ-4's Charles Benson that despite past GOP candidates’ poor showings in the Badger State, this year will be different. “Now we have photo ID, and I think photo ID is gonna make a little bit of a difference as well," he said.

Grothman said something similar in 2012, when he was minority assistant leader in the state Senate. At that time, he said the law, which he helped to pass in 2011, could help GOP presidential candidate Mitt Romney if it were in effect for the November election because “people who vote inappropriately are more likely to vote Democrat.”

The law, which has not been a factor until this cycle, limits the forms of identification accepted for individuals to cast a ballot and is considered one of the strictest in the nation. An estimated 300,000 registered voters in Wisconsin, 9 percent of the electorate, were considered at risk of being disenfranchised in Tuesday’s primaries. The law in Wisconsin, and in other states with similar rules on the books, predominantly affects certain groups: African-Americans, the poor, elderly individuals and students.

Conservatives often defend the laws as tools to guard against voter fraud, promoting voter integrity and even increasing turnout. However, there is almost no evidence that in-person voter fraud is a widespread issue. Conservative Judge Richard A. Posner of the U.S. Court of Appeals for the 7th Circuit bluntly characterized Wisconsin’s law as a "poll tax."

"There is only one motivation for imposing burdens on voting that are ostensibly designed to discourage voter-impersonation fraud," he wrote in an opinion for a case addressing Wisconsin’s law, "and that is to discourage voting by persons likely to vote against the party responsible for imposing the burdens."

Posner said the state's argument in favor of the law exists in a "fact-free cocoon," the Los Angeles Times reported.

The law contributed to hourslong lines at polling stations for the state's GOP and Democratic primaries, which Sen. Ted Cruz (R-Texas) and Sen. Bernie Sanders (I-Vt.) won, respectively.