SALT LAKE CITY (AP) — About a third of Utah’s registered voters are at risk of not being able to participate in March’s Super Tuesday presidential primary if they don’t request ballots. State and county election officials have been sending letters and trying to get the message out to independent voters before it’s too late. The state has nearly 510,000 independent voters who aren’t automatically sent a ballot. The Republican primary is closed, so voters who want to cast a ballot in the GOP race must register with the party by Feb. 3. The Democratic primary is open, so independent voters have until Feb. 25 to request that ballot.