Nightly News | September 30, 2012
>>> u.s. just three days now until the first presidential debate with the candidate spending the next few days intensely preparing for wednesday's showdown. kristen welker is traveling with the president in las vegas .
>> reporter: with four mock debates under his belt, the president will rally in nevada before jumping into the ring with his sparg partner mitt romney . president obama got another boost, leading governor romney by four points, 49% to 45%.
>> i want to see us export more jobs, export more products -- excuse me. i was -- i was channeling my opponent there for a second.
>> reporter: last week romney hinting at his debate approach.
>> he's trying to fool people into thinking that i think things i don't and that ends, i think, during the debate.
>> reporter: for days both sides have been tamping down expectations, today on the sunday talk shows.
>> he's prepared more than any candidate, maybe in history, certainly in recent memory.
>> sometimes we expect a major break through, the comment, that doesn't happen very often.
>> reporter: but on "meet the press," new jersey republican governor chris christie had a different take.
>> come sunday morning, the entire race is going to change.
>> i think my biggest concern now would just be for the -- -his mental well-being. i have all the confidence in the world in his ability, in his decisiveness, in his leadership skills.
>> reporter: today paul ryan admitted to missteps, including the 47% comment. but at the end of the day , we're giving people a very clear choice.
>> reporter: ryan was asked the specifics of the tax plan, both romney and ryan have yet to detail their tax cut . now romney is preparing for the debates in boston, massachusetts with senator rob portman standing in as president obama . he is working on sharpening his message. meanwhile obama campaign says that obama is working on shorter, crisper answers. before he gets started, he will speak at this campaign event right here in las vegas .
>> kristen welker tonight.