It's the same thing as Trump's financial records. On one hand, there's a legitimate concern. On the other hand, opponents are looking for looking for dirt. Opponents will gladly distort whatever the records say.
My dad is still going strong after having had a couple of heart attacks 30 years ago. We know what Sanders's records will say: lots of things opponents can use to claim his health is unfit for the presidency, even though he'll likely survive just fine.
Maybe I was wrong. Maybe it actually is like birthism, where every bit of documentation results in demands for even more documentation. But on the other hand, he's 78, and asking for more documentation may be legitimate.
