On January 21, 2010, 54 Representatives sent President Obama a letter that termed Israel's blockade of the occupied Gaza Strip as "de facto collective punishment" and called on the United States to press Israel "for immediate relief for the citizens of Gaza."
Some more info from James Wall:
Here's a PDF version of the letter, including the signatories. Cheer or jeer your rep, depending on whether you see their 'John Hancock.' (I recommend zooming in and then going fullscreen).
Letter from House Reps about Gaza