i am don hamilton. iowa residents will be casting their votes tonight, and republican residents are casting their last hopes on voters who are undecided. tracie potts reports from iowa. >> it confident mitt romney told iowa supporters he wants their help to make a barack obama a one-term president. >> i am here to collect. he is out. >> romney caucuses with a slim lead over ron paul and rick santorum in the latest poll. yesterday he predicted victory. today he was more cautious. >> i think i will be among the top group. i don't know if it is one, too, or three. >> romney spent a lot on tv ads but rick perry spent more. >> on to victory. >> this morning on cbs, newt gingrich accused romney of lying about who paid for some of the negative ads. >> are you calling mitt romney a liar? >> yes. >> you are calling mitt romney a liar? >> yes. >> will voters care? >> the rhetoric and policy positions and the campaign ads are not going to impact things as much on the final day of the caucus. >> for some of you is

don, and happy jack, arizona. rick parker from georgia. >> bob, fair banks, alaska. >> from hamilton, new zealand. >> i haven't mentioned much but the paper back is essential, essential reading for anyone want to go understand what is at stake in the upcoming election. by the way, happy early birthday. lincoln is on the way to kiwi land. and kenya. >> i think he's thanking me for the book. i didn't kill him. and if you become a premium member you get k. l. free of charge. good deal. from racine, wisconsin. >> since i'm the producer of the national geographic project, that might happen. i can just see me at the golden globes next year accepting the award for being the most modest commentator on the air. [laughter] >> no. >> finally, as you may know, tim tebow and the broncos got their butts kicked saturday night. but before the game he visited a 40-year-old who sustained a traumatic brain injury in a high school football game that left him mentally disabled. that was part of his foundation that scheduled a quarterback to visit a young person in need wherever he goes. while he lost the game saturday, he continues to be a