Why the old Mississippi-class ships were combat-obsolete

Were the two former US Navy Mississippi-class pre-dreadnoughts hopelessly obsolete against Stuka attacks?

Yes; their historical appeal did not give them a realistic chance against modern dive-bomber attack.

The two former US Navy Mississippi-class pre-dreadnoughts had little realistic combat value against Luftwaffe Stuka attacks. They were obsolete by this stage of the war, though still historically appealing. Interest in a surviving capital-ship design should not be confused with confidence in its contemporary fighting power. Modern air attack made the continued existence of these old ships a poor guide to their battlefield usefulness.