BOSTON, Mass. (SHNS)--Most Massachusetts voters will not have much of a choice to make for state representative and state senator on Tuesday, but there's still a lot at stake in the small share of contested races. When the next two-year term kicks off Jan. 1, 2025, more than one in 10 lawmakers will be newcomers to the job. Where to vote on Election Day in Massachusetts At least three new senators and 18 new representatives are guaranteed to be elected Tuesday thanks to a combination of seats opened up by retirements, lawmakers quitting their posts mid-term, and two incumbents who lost their reelection bids in the primary. Those numbers could grow larger if challengers topple more lawmakers this week. As has long been the case in Massachusetts, where interest in serving in the Legislature is low, only a fraction of districts feature actual decisions for voters. All 160 House districts and 40 Senate districts are up for election, but in 118 House districts and 28 Senate districts, only a single candidate is on the ballot. That means no change in the Beacon Hill power dynamics. Democrats hold 132 House seats and 36 Senate seats, and Republicans hold 24 House seats and four Senate seats. Independent Rep. Susannah Whipps of Athol is also serving, and there are three vacant House seats. Most of the action is concentrated in southeastern Massachusetts and Cape Cod, or in the central Massachusetts corridor north and south of Worcester, areas where Republicans have had some success over the years. That includes a pair of open Senate seats that could reshape the chamber's minority caucus. Two reps, Democrat Dylan Fernandes of Falmouth and Republican Mathew Muratore of Plymouth, are in a heated race to win the district that Democrat Sen. Susan Moran gave up to run for Barnstable County Superior Court clerk. They're both burning through campaign cash -- though Fernandes has been spending well above his opponent and most other lawmakers -- and clashing over topics such as state spending and how to navigate the emergency family shelter crisis. Although the district got reshaped in the latest round of redistricting, it's historically been competitive for both parties. Moran succeeded Republican Sen. Vinny deMacedo. He took over from Senate President Therese Murray, who spent 11 terms representing the area as a Democrat after unseating Republican Sen. Edward Kirby. Just next door to the west, another open Senate seat is drawing a lot of attention. Taunton City Councilor Kelly Dooner, a Republican, is hoping to flip a seat held for the last 31 years by retiring Democrat Sen. Marc Pacheco. Raynham Select Board Chair Joseph Pacheco -- who has no relation to the senator -- will try to keep the district blue. Dooner and other female Republican Senate candidates, Karla Miller of Lowell and Jeanna Marie Tamas of Winthrop, have a chance to become the first GOP woman in the Senate in two decades. The last Republican woman senator was Jo Ann Sprague of Walpole, who decided in 2004 not to seek reelection. Another somewhat purple area generating some buzz this cycle is the Worcester and Middlesex District represented today by Democrat Sen. John Cronin of Fitchburg, who faces a challenge from Republican Nicholas Pirro III of Lunenburg. Cronin first won the seat by toppling Republican Sen. Dean Tran -- who has since been convicted of wire fraud and faces other legal challenges as well -- in 2020. The Senate's four Republicans continue to operate with Bruce Tarr, a Gloucester moderate who sometimes reaches across the aisle to vote with Democrats, as their minority leader, a role he first took in 2011 from Richard Tisei. While the quartet are often in accord, Sens. Ryan Fattman and Peter Durant tend to lean more conservative than do Tarr and Sen. Patrick O'Connor. The more moderate pair are unopposed Tuesday, while Fattman faces a challenge from Democrat Anthony Allard of Monson and Durant will face Sheila Dibb of Rutland. Democrats will still hold a massive majority in the Senate after Tuesday's elections, but the results might tilt a critical mass of Republicans away from Tarr, or reinforce his standing. Over in the House, Republicans have also stood by their leader for an extended period. Minority Leader Brad Jones has held that position since 2002, when he took over from Francis Marini, who became a district court judge. Jones does not face any opponent Tuesday in his district that covers North Reading, Lynnfield and parts of Reading and Middleton.  Based purely on the last election's results, Republicans might conclude the most viable pickup is a House seat way up north. Democrat Rep. Kristin Kassner of Hamilton earned her first term two years ago by a single vote over veteran Republican Rep. Lenny Mirra following a recount. This cycle, she appeared poised to coast to reelection without a fight, but Republican Mark Tashjian of Georgetown got enough write-in votes in the primary to secure the party's nomination and an official spot on the Nov. 5 ballot. That's the same process that Dashe Videira of Franklin, a Republican, used to make the ballot against Democrat Sen. Becca Rausch. Republicans continue to target Rausch, who topped Republican Sen. Richard Ross in 2018 and prevailed over challengers in 2020 and 2022. The contests will be the first round of biennial legislative elections since both major parties installed new leadership. Amy Carnevale took over as chair of the MassGOP in early 2023, and the Massachusetts Democratic Party added Steve Kerrigan as its chair a couple of months later. Two years ago, Democrats bulked up their already-massive ranks to the largest margin since 2009. Republicans have not controlled either legislative chamber in Massachusetts since 1958, when they held a two-seat majority in the Senate. At this point, they're hoping to make inroads chipping away at a Democratic supermajority and to build on some special-election momentum after several years of upheaval under former Chair Jim Lyons. Durant won a November 2023 special election for the district last held by Democrat Sen. Anne Gobi, and Republican Rep. John Marsi then held onto Durant's former House seat in a subsequent special election that did not feature a Democrat on the ballot. MassGOP Chair Amy Carnevale said last week she is "more confident than ever in our chances to gain seats in the legislature." "The party has put in the hard work -- raising funds, implementing a strategic, cutting-edge approach, and positioning our candidates for success," she said. "Our candidates have been relentless: knocking on doors by day, making calls by night, and presenting their vision to voters across the Commonwealth. We're giving this election cycle everything we’ve got, and we’re ready to see the results on November 5th." MassGOP is only challenging in 13 Senate districts and 47 House districts, contributing to the Bay State's ranking as the least competitive legislative elections in the country. Party officials are again spinning their targeted approach as a smarter, more efficient use of resources, with races focused in areas they think Republicans have the best chance of winning. One Democrat they might view as vulnerable is Rep. Chris Flanagan of Dennis, whom state campaign finance regulators earlier this year accused of lying to them and obstructing a probe into his political spending. Gerald O'Connell of Yarmouth, another Republican who secured a ballot spot via a successful write-in primary, will try to unseat him. The most influential legislative Democrats will not have much to worry about, at least in their districts. House Speaker Ron Mariano, Senate President Karen Spilka, House budget chief Rep. Aaron Michlewitz and Senate budget chief Sen. Michael Rodrigues are all unopposed.