While I realize that we are a marginal community and that President Obama has much bigger things to worry about, the DOJ has wide latitude in exercising discretion in picking and choosing the matters it investigates and prosecutes, and ultimately the President is responsible for the DOJ's actions.
As Barney Frank pointed out, this is a highly questionable use of the DOJ's resources given that it is a consensual activity among adults for which the only federal appellate court ruling has held that the DOJ has no authority to regulate or prosecute. It's not as if there are not real federal crimes which the DOJ should be and addressing where they could better put such resources to use.
In fairness to the President, this is probably something that started under the Bush administration, but given the previous action of the DOJ last year, freezing select bank accounts that processed payments to online poker sites, it is something that he at least marginally became aware of at that time. He clearly doesn't seem to care, and it now seems abundantly clear which side of the line he stands. Focusing our efforts on legalizing poker requires that we not fool ourselves into thinking otherwise.