New Reuters/Zogby national poll out (Nov 14-17, 545 Dem LV, MoE +/- 4.3%; 503 GOP LV, MoE +/- 4.5%). On the Democratic side, Clinton's lead over Obama has shrunk by a net 10-points in the last month:

Democrats
Clinton 38 (-8 vs. last poll Oct 10-14)
Obama 27 (+2)
Edwards 13 (+4)

Overall, Clinton leads by 19.7% in the RCP Average.

On the Republican side, Giuliani increases his lead over the field by virtue of Thompson's decline, and Mike Huckabee surges into third place:

Republicans
Giuliani 29 (+1 vs. last poll Oct 10-14)
Thompson 15 (-5)
Huckabee 11 (+7)
McCain 9 (+1)
Romney 9 (-5)

Overall, Giuliani leads by 13.2% in the RCP Average.