For decades, candidates for the Palo Alto City Council have tended to coalesce into one of two camps: those who believe that the city could and should support more development and those who prioritize protecting neighborhoods from the impact of growth.

Some of these patterns continue to hold in the current election, even as the community conversation has evolved and just about everyone acknowledges the need to build more housing, particularly of the affordable variety.

Backing candidates Ed Lauing and Doria Summa, who respectively serve as chair and vice chair of the Planning and Transportation Commission, are city leaders who in the past have supported "residentialist" policies such as lower limits on nonresidential development, retaining the city's 50-foot height limit for new buildings and generally opposing development projects that require exceptions from zoning codes.

Former council members Karen Holman, Greg Schmid, Enid Pearson and Emily Renzel and current council members Tom DuBois and Eric Filseth support Lauing and Summa. Both DuBois and Filseth joined the council in 2014 as part of a residentialist resurgence that followed a 2013 referendum over a housing development on Maybell Avenue.

Those who have supported faster city growth are reliably rallying behind two other candidates: author Julie Lythcott-Haims and Lisa Forssell, a member of the Utilities Advisory Commission. Each counts among their list of endorsers former council members Marc Berman (who is currently serving in the state Assembly), Larry Klein, Dena Mossar, Gail Price and Betsy Bechtel.

The exception appears to be candidate Vicki Veenker, who is attracting supporters from both camps. The attorney and mediator has support from a candidate committee that is associated with Klein and housing advocate John Kelley. But Veenker also has the support of DuBois, Filseth and Mayor Pat Burt, a political centrist.

Burt, who has also endorsed Lauing, initially supported Forssell before recently withdrawing his endorsement from her and giving it to Summa.

These five candidates, along with Realtor Alex Comsa and software engineer Brian Hamachek, are vying for three seats that will be vacated at the end of the year when DuBois and Filseth term out and council member Alison Cormack completes her first and only term.

Burt said the issue that made him change his endorsement is housing. Every candidate has said that housing, particularly affordable housing, is a critical priority. Summa, he said, embraces new housing but is realistic about the challenges of accommodating it.

Forssell and Lythcott-Haims, meanwhile, have been more enthusiastic than other candidates about meeting the state's housing mandate of 6,086 new units by 2031 and about embracing recently adopted state laws like Senate Bill 9, which allows owners of single-family homes to split their lots and build up to six residential units: a primary home and two accessory dwelling units on each of the two new lots. Forsell wrote in a response to a Palo Alto Neighborhoods survey that SB 9 is "a reasonable tool to have available for homeowners who want to tap into their home equity, provide a place for a family member to live, or generate rental income."

But Burt said, "When candidates say SB 9 doesn't go far enough, that is expressing an interest in having local zoning change that would exceed SB 9, allowing large apartment buildings."

But Burt said he disagrees with the position that the housing mandate can be achieved without significant impacts on the city and that the recent state laws do more good than harm. Forssell's stance on housing mandates, he said, prompted him to pull his endorsement from a candidate for the first time ever.

Summa and Lauing, he said, recognize that challenge and, while embracing affordable housing, "have been cautious about the feasibility of actually achieving those units."

The big difference between candidates, Burt said, is that some "embrace state mandates that are nearly unachievable and desire even higher mandates, versus candidates who recognize that those state mandates will be extremely difficult to meet and probably not possible."

Summa, he said, "embraces significant new housing but has been realistic about the challenges of actually achieving that.

"And these are in my mind almost insurmountable challenges, even though we are and should do as much as we can to come as close as we can to achieving those numbers," he said.

Lythcott-Haims' and Forssell's enthusiasm for residential growth has netted support from people like Price, who serves on the board of nonprofit Palo Alto Forward, which advocates for more housing, and past and present council members who have tended to support more development (current council member Greg Tanaka, for example, endorsed Lythcott Haims; former council member Greg Scharff, who serves with Forssell on the Utilities Advisory Commission, endorsed her council campaign).

Cormack believes that Lythcott-Haims and Forssell are best suited to tackle the housing issue, which Cormack said is the biggest issue that divides the candidates in the council race. Over her years on the planning commission, Summa has established a reputation for being a tough critic of new developments. This includes being as the sole dissenter on residential projects at 788 San Antonio Road, which includes 102 apartments, and a mixed-use proposal with 17 dwellings on the former site of Compadre's Restaurant. Though Summa said she favored the San Antonio housing, she felt that the city was moving too fast to change the broader zoning rules.

While the planning commission is no longer as factional as it has been in the past, Lauing has tended to vote with the more slow-growth faction. Last year, for instance, he joined Summa in opposing the most aggressive growth alternative for the North Ventura Coordinated Area Plan, a vision document for a 60-acre portion of the Ventura neighborhood (the council ultimately rejected this alternative as well). Both are endorsed by Palo Altans for Sensible Zoning, a political action committee that supports candidates affiliated with the council's more slow-growth wing.

"I think it's very easy to say you're for affordable housing," Cormack said. "I think the rubber meets the road when you need to make a decision on how many units are going to go into a specific place that provides a place for people to live," Cormack said. "And fundamentally that is where we are. It's the devil in the details about parking and height limits and all those things that make each of those decisions difficult."

While she is not affiliated with the committee supporting Lythcott-Haims, Forssell and Veenker, Cormack said she backs all three candidates for various reasons. She has known Lythcott-Haims for 35 years and said she has been influenced by her teachings, particularly on issues relating to police reform.

"Her ability to communicate hard truths is just what our council and community needs," Cormack said.

She also lauded Forssell's experience in the field of sustainability, which Cormack called the most critical issue that the council is facing. Her experiences at the utilities commission and the way she does her work are "really well suited to the work we need to do on climate change over the next eight years if we have any hope of meeting our goals," she said.

Despite their philosophical differences on housing, Burt and Cormack both support Veenker. Cormack lauded her experience in bringing different factions together and believes she is "committed to finding common ground in a reasonable manner." Burt agreed.

"She embraces significant new housing but has been realistic about the challenges of actually achieving that," Burt said of Veenker. "And these are in my mind almost insurmountable challenges, even though we are and should do as much as we can to come as close as we can to achieving those numbers."