Of the 10 contested primary races to be decided today, the race in Ward 7 between incumbent Doug Hausladen ’04 and Ella Wood ’15 is one of the most contentious.

Ward 7, which includes sections of East Rock and much of New Haven’s downtown, is among the most diverse in the city — bringing young urban dwellers, Yale professors and a significant business community into a single district. Because of the competitiveness of the race and the diversity of the ward, it is a bellwether for the rest of the city.

Tuesday night’s outcome is likely to provide an indication as to whether the 2011 election, which swept the city’s unions into power, is a singular occurrence or an ongoing trend. It will also provide a measuring stick for the organizing power of both the unions and a new force in Elm City politics, Take Back New Haven, which aims to maintain a diversity of thought on the board.

“I have no data to tell me that I’m going to win this election tomorrow,” Hausladen said. “And because of that I’m not going to sleep until polls close at eight o’clock Tuesday night.”

Wood, an Ezra Stiles junior from Albuquerque, N.M., began her candidacy in early August within a week of moving into the ward. Prior to moving into her residence on Humphrey Street, she lived a short distance away in Ward 2.

The 2008 Obama presidential campaign served as Wood’s first experience with politics. After coming to Yale in the fall of 2011, Wood involved herself with Students Unite Now, an affiliate of UNITE HERE, which includes Yale unions Local 34 and Local 35 and is the largest organized labor force in the city. During the past summer, Wood worked at UNITE HERE and advocated for New Haven Works and New Haven Rising, two projects that emerged from the labor-backed coalition of 20 aldermen on the board.

The association has led many to tie Wood’s candidacy to UNITE HERE, although both Wood and union leadership deny that she ran at the behest of the unions. Wood initiated her run about six weeks after Hausladen formed Take Back New Haven, a slate of candidates dedicated to countering the labor-backed “supermajority” on the board.

“I personally think very highly of her, but nobody in that race got our endorsement,” Local 34 President Laurie Kennington said.

The two candidates contrasted their visions for the ward and the city in a debate Thursday night. Attended by about 60 residents of the ward, Hausladen made extensive use of his intricate knowledge of the ward, noting the names of panhandlers in the ward and examples of small but specific improvements he has brought about in the neighborhoods.

Hausladen’s two-year aldermanic record has endeared him to many in the ward, including Ward 7 Co-Chair Alberta Witherspoon. The co-chair cited Hausladen’s leadership in fixing crosswalks along Audobon Street as an example of his commitment to prioritizing Ward 7 constituents. Witherspoon articulated the difference between Hausladen and Wood not as one based on union affiliated, but rather familiarity of the ward.

“Doug supports the unions. My co-chair and I support the unions. I used to be in the unions,” Witherspoon said, but went on to emphasize that Wood has at best a cursory knowledge of the ward. “I’ve been here for years and there are things that I’m still learning.”

Hausladen said that although the outcome of the race is uncertain, his campaign has identified hundreds of supporters in the ward, all of whom they plan to contact during today’s “get out the vote” effort. Although only about 350 Ward 7 residents voted in the last aldermanic election, Hausladen suggested that the mayoral race might bring as many as 800 or 900 to the polls.

Wood also said that supporters would knock on the doors of potential voters throughout the day Tuesday, but was unable to say how many volunteers she expected. Despite her union ties, Wood’s campaign staff will be separate from union campaign staff.

“We’re going to have a strong team of people out in the field. I’ll be at the polls the whole day,” Wood said. “We’ll be bringing people in down to the very last minute.”

Across the city, nine other wards — 2, 8, 11, 14, 19, 20, 22, 26 and 27 — will have contested aldermanic races on today’s ballots. Three of those races include candidates affiliated with Take Back New Haven: Greg Smith in Ward 2, Peter Webster in Ward 8 and Patty DePalma in Ward 11. Anna Festa, who is running unopposed in the Ward 10 primary, and Mike Stratton, who is running in Ward 19, were previously part of the group but have since left.

In eight of the nine contested races, candidates have filed petitions to run as Independents should they lose in the primary. The practice mirrors that of the three mayoral candidates — Elicker, Fernandez and Carolina — who have vowed to fight on in if they are defeated today.

Of the 30 current members of the board, five chose not to seek re-election, including Ward 10 Alderman Justin Elicker FES ’10 SOM ’10. In addition, Republicans will contest the aldermanic races in wards 1, 6, 8 and 10 during November’s general election.

Slightly over 4,500 Elm City residents live in Ward 7, of whom 1,700 are registered democrats.