I imagine there would be significant voter anger if the amendment passes 50, especially if convincingly, but fails to clear 60%. Might be the FLDP’s last hope for a win in 2026, but they’d probably blow that opportunity, too.
Every single Yes voter will know if that if Biden wins and Democrats control Congress, they can pass through this amendment nationwide by codifying Roe. So the campaign will be "Yes/Biden/D Senate/D House" and be really good for all of the Democratic candidates.
Republicans might end up wishing they just had the 50% threshold and let this pass in Florida rather than letting Florida be the difference in Congress enacting it everywhere.