People can argue until they are blue in the face, but this is reality in the 21st century: Anyone who is a citizen by birth, be it to citizen parents or birth on US soil, is eligible to be President. It applied to Obama, Ted Cruz and John McCain, and it applies to Harris. Attacking her with this argument is counterproductive and will just make her a more sympathetic candidate. It will help them build a false narrative of an underprivileged child rising above discrimination and racism. I guess the folks who pushed the Obama birther stuff figure that worked out so well, why not try it again?
McCain was a US citizen. His US citizen parents were serving in Panama Canal. Otherwise no pregnant US Mother would leave the USA.