While New York state political observers are captivated by the drama over a deal between state Senate Minority Leader Andrea Stewart-Cousins and Independent Democratic Conference Leader Jeff Klein to reunify Democrats in the state Senate, control of the chamber may actually be determined by the outcome of a special election in Westchester later this month.

Who wins former state Sen. George Latimer’s open seat could also be a bellwether for races around the state, indicating whether Democrats will have a wave election in November, and who will ultimately have control of the state Senate.

The deal between the IDC and mainline Democrats had initially been contingent upon victory by Democratic candidates in upcoming special elections. On April 24, elections will be held for 11 vacant legislative seats, including two in the state Senate. One of these seats, formerly held by New York City Councilman Ruben Diaz Sr., is in a safely Democratic district in the Bronx. The other, which was vacated by Latimer, now the Westchester County executive, has a history as a battleground district. Democratic Assemblywoman Shelley Mayer and Republican Julie Killian, a former Rye city councilwoman, are vying for the seat. The winner will have to run for reelection in November.

The suburban Senate seat has been a swing district. Republican Bob Cohen lost narrowly to Democratic incumbent Suzi Oppenheimer in 2010 and to Latimer in 2012. Westchester County was previously led by Republican Rob Astorino, who launched an unsuccessful gubernatorial bid in 2014 and was defeated by Latimer in an upset victory in 2017.

Jeanne Zaino, a professor of political science at Iona College, said that the race between Mayer and Killian is closer than many observers had expected given the advantage Democrats have in enthusiasm. Zaino noted that one of Killian’s strategies has been to tie Mayer to the aura of corruption that permeates Albany. Mayer was chief counsel to state Senate Democrats from 2007 to 2011, during which time the Senate Democratic leaders were Malcolm Smith and John Sampson, who were later convicted of corruption in separate cases.

“Killian is trying to pitch Mayer as the incumbent, if you will, and the insider, and painting herself more as the underdog and the outsider,” Zaino said, noting that dissatisfaction with the political establishment was an important theme in the 2016 presidential election.

Michael Lawler, Killian’s campaign manager, said that corruption in Albany is an important election issue, and that voters want to ensure that one party doesn't have full control of the state.

“You have a Democratic governor and a Democratic state Assembly, and so having a Republican majority in the state Senate to provide balance in state government is important,” Lawler said. “I think a lot of people want to ensure that one-party rule in New York state doesn't happen.”

However, the desire to see a balanced government may be outmatched by the strong Democratic headwinds going into the 2018 midterms, both in New York and nationally. President Donald Trump is deeply unpopular in New York state, and recent races – including in Westchester – have seen a surge in Democratic enthusiasm.

Zaino said that when she did polling in the 2017 race between Latimer and Astorino, she found that 4 in 10 voters said that Trump would be a factor when making their decision about who to vote for in the county executive race. That dynamic was continuing to play out in the race between Mayer and Killian, she said, as Westchester residents often want to talk about national politics in conjunction with this race.

The interest in national politics has led to an unusual level of voter and activist engagement for a local special election. Doug Forand, a spokesman for Mayer’s campaign, said that the campaign was sending out 100 volunteers each weekend to canvass.

“I've never seen the kind of volunteer effort that is coming through for this race,” he said. Forand conceded that the campaign would have to work to ensure strong turnout, as voter participation is generally low in special elections. However, he remained optimistic that Democrats and independents would vote for Mayer because “they're so upset about what's happening nationally.”

But Lawler argued that voters would be more concerned with district-specific issues than with national politics when voting.

“I think voters are very concerned about what's going on locally and in New York state, and those are the issues that we're focused on, and that Julie's been addressing every day since getting in the race,” he said. “The political climate is certainly against Republicans at the moment, but Julie is defying that.”

Even as Democrats generally emphasize national politics, Mayer has campaigned on the district’s specific issues – including the opioid epidemic, taxes and gun control – to woo local voters. Meanwhile, independent expenditure groups have poured money into the race, including charter school and education reform supporters backing Killian. Both candidates have peppered local media with ads.

While Trump has indirectly influenced the race, other major political players have gotten directly involved. Cuomo has endorsed and held a rally and a fundraiser on behalf of Mayer, and former Gov. George Pataki is supporting Killian. Since the race may determine party control in the state, big dollars and big names are flooding the district.

The IDC reunification deal might harm Mayer, as it would take away her argument to turn out Democratic voters that she must win for the IDC to return to the fold. But Democrats still need to hold her seat to gain the majority. Her campaign argues that, thanks to the IDC agreement, she can now point to a greater likelihood of actually being in the majority and having the power to get legislation passed.

“People vote much more on the individual than they do based on the insider, macro political battles that are going on,” Forand said. “I think it's good for what Shelley would be able to achieve as a senator, and I think that's going to be great for her in November.”

Lawler agreed that the reunification announcement will not have an effect on the race’s outcome. “Ultimately, voters in this district are not going to be swayed by the machinations of the Albany power brokers,” Lawler said. “They're going to be swayed by who is best suited to address the issues and concerns of the community here.”

Lawrence Levy, executive dean of the National Center for Suburban Studies at Hofstra University, said that how suburban Westchester residents vote could even be an indicator of state or even national headwinds.

“What happens in this district not only may determine control of state government, which is important enough,” Levy said. “The performance of these swing suburban voters could serve as a bellwether for the political direction of the entire country.”