(Scott Audette/Reuters)
Gallup. 10/3-7. Republicans. MoE 4%. (9/15-18 results).
Romney: 20 (24)
Cain: 18 (5)
Perry: 15 (31)
Paul: 8 (13)
Gingrich: 7 (5)
Bachmann: 5 (5)
Santorum: 3 (2)
Huntsman: 2 (1)
Other: 1 (4)
Undecided: 20 (10)
Aside from the obvious—Romney being flat, Cain surging and Perry collapsing—it's noteworthy that the undecideds shot up by 10 points.
Still, if you're trying to figure out what this all means, consider where things stood at this point in October 2007 on both the GOP and Democratic sides: McCain was in third, 16 points behind Rudy Giuliani, and Obama was in second, 21 points behind Hillary Clinton.
If you're interested in the longer-term trends, here you go:
Notice that although Mitt Romney has been the most consistent candidate in the top tier, even at his peak (27 percent in June) he had less support than Perry in July (27 percent) or September (31 percent).