PROVIDENCE, R.I. (AP) — Rhode Islanders casting a ballot in Tuesday’s primary elections will settle a bitter matchup between U.S. Rep. David Cicilline and businessman Anthony Gemma while giving the state’s new voter ID law its biggest test yet.

They also will pick winners in dozens of state legislative primaries and will decide a four-person Republican contest in the state’s 2nd Congressional district.

Polls will open at 7 a.m., except in Block Island where they open at 9 a.m. All polls close at 8 p.m.

The hottest race on Tuesday’s ballot is between Cicilline and Gemma. Cicilline, a freshman and former mayor of Providence, has tried to keep the race focused on the economy and his efforts to thwart the Republican agenda in Washington. Gemma spent much of the campaign attacking Cicilline’s character, leveling unsubstantiated allegations of voter fraud against Cicilline’s past campaign and saying he misrepresented Providence’s financial health before he left City Hall.

Perennial candidate Christopher Young also will appear on the Democratic ballot. The 1st District covers eastern Rhode Island and most of Providence.

The winner will face Republican Brendan Doherty, the former leader of the state police, in the Nov. 6 general election.

Four Republicans are vying for the nomination in the state’s 2nd Congressional district, which covers western Rhode Island and some central parts of Providence. They are Michael Gardiner, Michael Riley, Donald Robbio and Kara Russo.

Incumbent U.S. Rep. James Langevin faces John Matson in the Democratic primary.

In the U.S. Senate, Democratic Sen. Sheldon Whitehouse and his Republican challenger Barry Hinckley stand unopposed on the primary ballot.

In the General Assembly primaries, attention has focused on state Senate races that could decide whether the General Assembly votes next year on gay marriage legislation. Gay marriage advocates are supporting several challengers working to unseat gay marriage opponents. Legislation to recognize gay marriage failed last year after it became apparent it would not pass the Senate.

Tuesday’s election will likely be the first time many voters are asked to present identification at the polls since the state’s new voter ID law took effect. Acceptable forms of identification include a government-issued document like a Social Security card, passport or driver’s license, or a bus pass, bank statement or employee ID. Voters who lack the right documentation will be given provisional ballots.

The new law caused few problems during two local elections earlier this year and the state’s presidential primary in April, according to Chris Barnett, a spokesman for Secretary of State Ralph Mollis. Those three elections saw only 25,000 ballots cast, and Tuesday’s primary is likely to see a much larger turnout.