Jewish law (Halacha) permits American Jews to celebrate Thanksgiving because it is a secular holiday. Furthermore, "giving thanks" has always been an important part of Judaism, from reciting blessings after meals to the pilgrimate festival of Sukkot.
Thanksgiving evokes warm associations--a Norman Rockwell "Freedom from Want" photograph, a midweek vacation from work, "meshpocheh" (family) and friends gathering, an abundance of "geshmak" (delicious tasting) food, and football.
This year, "Ver volt dos geglaibt?" (Who would believe it?), Hanukkah begins at sundown the day after Thanksgiving.