Speaking on the issue of homeland security before a fund-raiser for Republican Senate candidate Doug Forrester, the president said, "The House responded, but the Senate is more interested in special interests in Washington and not interested in the security of the American people. I will not accept a Department of Homeland Security that does not allow this president and future presidents to better keep the American people secure."
As you note, the President was not referring to the Senate vote on Iraq, but the vote on the Department of Homeland Security. Moreover, the President didn't accuse Democrats! Instead, his dart was launched at the institution, the Senate -- it was a "bi-partisan scolding".
Thus, it was Li'l Tommy that turned this into a partisan issue. As to which, I say to Li'l Tommy: if the shoe fits, then wear the SOB.