I think it's pretty hilarious that the airlines are critical.
The last time I flew, I needed my military ID, a passport, a registration form, and a ticket to get on a jet out of Atlanta. Now I would need an additional COVID test as well.
Is there a Constitutional amendment (e.g., the 15th) or an Act (e.g., Voting Rights) to give you the right to board an airplane?
Does the functioning of a democratic republic rest on your ability to fly? When voting is made more difficult, or even more inconvenient (in any way) for people who are eligible to vote, who does that benefit? There is no problem of "illegitimate" voters in any significant numbers. Republicans have moved mountains for decades to find "voter fraud" and only come up with double-digit numbers out of billions of votes. It's a solution for a problem that doesn't exist and an offense to the concept of democratic elections.
The only things I have had to show ID for in many years are to rent a car or to buy alcohol (with a credit card at the state-controlled alcohol stores). Don't even need it to write a check at the grocery stores.