Domains can expire, be sold, have their hosting (nameservers) changed…etc it’s very conceivable given the current climate that it could be a malicious site used for data exfiltration from prospective voters. The security posture, if any, of the owner are also unknown, meaning it may be unknowingly compromised.
Especially when you have people willing to drop tens of millions of dollars on voter suppression.
Plain and simple, don’t enter your personal information into a 3rd party site. Use your official government provided ones for this purpose.