ST. PAUL — The leader of the Democratic Party in Minnesota on Thursday endorsed an effort to protect the privacy of voters who are required to declare a party preference to participate in the state’s March 3 Super Tuesday presidential primary.

State Chairman Ken Martin said at a news conference that he backs a proposal by Democratic Secretary of State Steve Simon and a bipartisan group of lawmakers to tighten control over what the parties can do with that participation data. The National Democratic and Republican parties require state parties to collect that data. But current Minnesota law places few restrictions on how the state parties can use it.

Under the Democratic proposal, only the national parties would get the data and they could use it only to guarantee the validity of the primaries. Otherwise, the data would be kept private, and voters could opt out of having that data collected when they vote in the presidential primary.

Early voting began Friday. Martin urged lawmakers to pass the changes quickly during the upcoming session, which opens Feb. 11, to keep the data private before the secretary of state must turn it over to the state’s four major party chairs. Two pro-marijuana parties have major party status in the state.

Minnesota GOP Chairwoman Jennifer Carnahan called the Democrats’ concerns “baseless” and said in a statement that they’re more concerned about the pro-marijuana parties using the data to siphon off Democratic votes.

Republican state Sen. Mary Kiffmeyer, a former secretary of state who’s influential on election issues within the Senate Republican majority, told Minnesota Public Radio last week that discussions of changing the law are premature when there have been no demonstrated problems. As chair of a committee with jurisdiction over election laws, she’s in a position to block any changes.