The people eligible for passports are not the same group of people eligible for voter id since there are a few jurisdictions where non-citizens can vote in certain elections. Voting is also a responsibility of the states (even at the federal level), so there isn't really such thing as a federal voter id since each state has different eligibility requirements for voters that don't necessarily align with passport eligibility. Additionally, passport cards aren't interchangeable with passports in most countries.

Also, every four years? Elections happen more or less constantly in this country at some level or another. Federal elections are every two years, BTW, and that's if we ignore special elections for federal candidates. You should learn more about the system you live in.

The current round of stop-and-search would be enabled by making passport cards or some form of universal id. The current legal reality is that you do not need to prove your citizenship on demand if you are already in the US as a citizen. The burden of proof - rightly in my opinion - lies with the government to prove that you are not a citizen. Frankly, I'm quite uncomfortable with "paper's please" entering the US law enforcement repertoire. The fourth amendment was pretty clear about this.

With the CBP using mere presence validated by facial id only at legally protected protests as reason to withdraw Global Entry enrollment, it seems more and more clear that we do not need to be giving more power to the people who do not understand the 4th and first amendments. Removing people from Global Entry for protected first speech is, afaict, directly in violation of the first amendment even if Global Entry is a "privilege"