Ted Cruz’s campaign is under fire for trying to pressure Iowa voters into participating in Monday’s caucus.

The campaign sent potential caucus-goers a mailer telling them to vote. The design resembled an official notice and it warned Iowans of “low voter turnout in your area,” the New York Times reports. It included records of people’s voting history with scores and percentages attached to them, telling voters: “CAUCUS ON MONDAY TO IMPROVE YOUR SCORE.”

Iowa’s secretary of state, Paul Pate, told Fox News that the mailer goes against “the spirit of the Iowa caucuses” and “misrepresents Iowa election law.” There is no penalty for not voting, so the scores mean nothing. In response to criticism he received, Cruz said: “I will apologize to nobody for using every tool we can to encourage Iowa voters to come out and vote.”

His campaign’s Iowa state chairman said that it’s a common practice. “Our mailer is modeled after the very successful 2014 mailers that the Republican Party of Iowa distributed to motivate Republican voters to vote, and which helped elect numerous Republican candidates during that cycle,” he told the Times. According to Republican strategist Rick Wilson, it’s a risky tactic. He told Fox News that successful social pressure is subtle, but “This, on the other hand, is like a sledgehammer.”

President Obama undertook a similar strategy to encourage voter turnout during the 2012 race, a move that was also met with criticism.