On Wednesday, advisers told reporters during a conference call they were confident they had broadened the battleground by spending money on ads in Minnesota, Michigan and Pennsylvania. ''I think we're in a great position to win [those states],'' senior adviser Russ Schriefer said. ''Can we win all of them? Probably not.
Can we win some of them? I think probably so.''
The Obama campaign responded with its own ad spending, though its chief adviser, David Axelrod, declared on morning television he would shave off his moustache should Democrats lose those states.
In previous elections this have been a clearer indication Republicans were confident of winning Florida and Virginia - traditionally Republican states that were won by Mr Obama in 2008 that Republicans lead in some polls - as well as Ohio. But this year both parties and the groups supporting them are brimming with cash due to relaxed donations laws, so the investment of time by the leaders and their key surrogates has become an increasingly crucial indicator of strategy and confidence.
On Wednesday, Mitt Romney spent all day in Florida, on Thursday he divided his time between Virginia and Ohio. Only on Friday did Mr Romney finally dedicate a full day to Ohio. To grasp how these tea leaves are being read, you need to look back to the electoral map.
The president is not elected by popular vote but by the Electoral College. is allocated college votes proportional to their population. There are 538 votes in total, so to secure the White House a candidate must win 269 votes plus one for a majority.
