His residence, no matter how small, or how often visited by him, was his home for voting and residency requirements while a Senator in the U. S. Congress.
I suppose it is very selfish for him to want to live with his family full time while he served as a Senator. That would be almost Criminal to the Pittsburgh Pack of Crap, I mean Post-Gazette, but it is not only legal, it is expected that a Senator with young children would live with them in the DC area. Ask Al Gore where he grew up, It wasn't in TN.
No he wasn't. No on is ENTITLED to other taxpayers' money. He should put his kids in the school in VIRGINIA, where he owned and lived all around the year in a $2 million mansion. Because he wasn't entitled to Penn Hill district money, and because at he was a (R)Senator under a (R)admin., the Department of Education tried to patch up the dispute, and in 2008 paid the Penn Hills district a sum of $55,000 (from taxpayers' money) to close the case. Santorum himself refused to reimburse a cent.