Former Gov. Charlie Crist has grown his lead over incumbent St. Petersburg Mayor Ken Welch, while Welch’s support has plummeted and the pool of undecided voters is shrinking.

A St. Pete Polls survey taken this week found Crist with nearly 28% support, more than 12 percentage points ahead of Welch and more than 17 points ahead of the rest of the mayoral race field.

When taking into consideration where voters are leaning on their voting decision, undecided voters shrink from 31% to 27%, and Crist’s lead grows more than others, indicating Crist’s support is on the rise, while Welch’s is on the decline.

Nearly 30% of voters say they either support Crist or are leaning in his direction. That’s a more than 4-point gain in support. Welch, meanwhile, gained less than a percentage point when considering voters who are leaning toward a preferred candidate, from just over 15% to 16% support. When considering leaners, Crist has opened a nearly 14-percentage-point lead over Welch.

City Council Member Brandi Gabbard was the only other candidate in the field to hit double-digit support, and just barely, with 10% support and nearly 11% when considering leaners. Former St. Pete Fire Chief Jim Large, jail administrator Maria Scruggs and former Shore Acres Neighborhood Civic Association President Kevin Batdorf all posted single-digit support.

The numbers are even more stark when considering past polling. A March poll, also conducted by St. Pete Polls, found Crist with 23% support to Welch’s 19%. When considering leaners, Crist’s support has increased about 7 percentage points since March, while Welch’s has dropped 3 percentage points.

Both the March and June surveys also queried likely voters on a head-to-head matchup between Crist and Welch. Both found Crist with the edge, but Crist performed even better in the June poll. The March poll had Crist with a 5-percentage-point lead, at 36% to 31%, while the June poll showed Crist with an 8-percentage-point lead, at 40% to 32%.

Welch’s backslide is unsurprising when considering his job approval numbers. The March poll found Welch above water by 7 percentage points, with a 39% approval rating to 32% disapproval. Now, the poll finds Welch 5 points underwater, at 35% approval to 40% disapproval.

The latest poll shows Welch’s support declining among Black voters, a bad sign for the incumbent who is serving as the city’s first Black Mayor. In March, Welch led among Black voters with 55% support, a huge lead over Crist, who posted just 16% support. But Crist gained 14 percentage points in the latest survey, while Welch slipped 13 percentage points, to just 42% support and only 12 points ahead of Crist among that demographic.

Other demographics are also trending in Crist’s direction, with the former U.S. Representative pulling nearly 29% support among Democrats compared to just 22% for Welch in the full Primary field, including voters who are leaning toward a particular candidate.

Head-to-head, Crist leads Welch by 8 percentage points, but his support among Democrats trails Welch, at 34% to 41%. Crist more than makes up for that among Republicans, at nearly 48% to 22%. Independent voters also break for Crist, at 42% to 28%.

But if polling trends continue, it’s possible Welch could never face Crist in a head-to-head matchup.

If one candidate receives more than 50% of the vote in the Aug. 18 Primary, there won’t be a runoff. Given the large field of candidates, 50% is a difficult threshold to reach, but with nearly a third of voters still undecided, it is possible.

It is also possible that another candidate could surge past Welch if his approval continues to decline, which would force a runoff with no incumbent on the ballot.

That’s important to note because the poll was taken before voters had seen a new ad attacking Welch over his absenteeism at City Hall. The ad drew attention to a Tampa Bay Times report showing Welch had shown up to City Hall just 34% of workdays during his first eight months in office.

And Crist has the resources to get his message out, with a $1 million lead in fundraising over Welch.

That money lead will allow Crist’s official campaign to share positive messaging about him, while his affiliated political committee is free to both share positive messaging about Crist and negative messaging about Welch.

The St. Pete Polls survey was taken June 29-30 among 451 likely St. Pete voters. Voters who said they didn’t plan to vote were excluded from the results. The poll has a 4.6-percentage-point margin of error.

— Ed. note: This story was drafted with assistance from AI. Editorial judgment, sourcing, and final review were performed by Peter Schorsch and the Florida Politics editorial team.

— Ed. note: Michelle Todd Schorsch is the Chair of St. Pete Shines, a political committee backing Crist for St. Petersburg Mayor. Todd Schorsch is married to Schorsch, the publisher of Florida Politics.