Get a dog, preferably one accustomed to cats? Maybe while you're away you could borrow one from a friend (who might tend your cats when they feed their dog - who's tethered near the kitty door).

As noted, compared to the average cat a racoon is a tank. Compared to a racoon, the badgers in my area are a tank batallion. (Or at least an explosive demolition squadron.) Neither will usually be much of a threat to a even modestly sized dog that can't get them cornered.

John