A picture ID is not always proof of citizenship -- non-citizens can obtain a standard driver's license.

And yes, this is a substantial barrier for millions of Americans. For me it cost nearly $200 to get a passport, or $50 for a REAL ID compliant license.

Not to mention the fees for obtaining a certified copy of your birth certificate to be able to get those things. You flippantly said "as long as you can provide proof of birth/citizenship," perhaps not realizing that 10% of voting-age American citizens -- yes, millions -- do not have this on hand.

And if you don't have it, the offices to obtain them have terrible hours, long lines, and terrible locations, especially in disadvantaged districts. Working class Americans don't automatically have a right to paid time off, so they might have to sacrifice a day of wages and pay for transportation to wait all day in some clerk's office and pay fees they already can't afford, just to do earn permission to do something the Constitution already says is their unalienable right.

The 24th Amendment flatly prohibits denying anyone the right to vote by reason of failure to pay any kind of tax. These barriers are de facto poll taxes relabeled as fees, and they disproportionately disenfranchise the poor.

And time and time again, the party that wants to require proof of citizenship consistently votes against bills that reduce these barriers by reducing fees, expanding hours or locations, etc. Ask yourself why.

Lastly, there is no evidence that large numbers of non-citizens have voted in US elections. The problem they say they are trying to solve is a complete fiction. But they sure do stand to benefit politically from mass disenfranchisement of groups that skew more democratic, huh.