Do we need federal regulations on interstate wine shipments?

I visit the NYT foodie blog "Diner's Journal" a couple of times each week to keep up with the NYC restaurant scene and catch Mark Bittman's latest recipes in his Minimalist videos.  This week, there is an entry about a bill in the U.S. House of Representatives that would impose federal regulations limiting the shipment of wine across state borders. 

At first glance one would think that this is an unnecessary intrusion into a matter best left to the states.  Who says we need this federal regulation?  Why no other than a confederation of beer and wine wholesalers.  As various states have allowed their citizens to import wine from other states (either direct from the winery or through an internet-based retailer), wholesalers have been cut out of an increasing share of the trade.  Of course this is not what they argue, instead the bill's supporters say they are trying to better protect minors from alcoholic beverages. 

And who says bipartisanship is dead in D.C.?  There are 150 co-sponsors of the House bill, with both parties well represented.  Accepting campaign contributions from the wholesalers is an issue many House members can agree on.