Politicos have always focused on fundraising numbers as a measure of the health of a campaign. Most recently, there is ruckus over President Obama's assertion that he will be 'outspent' by Romney. But the focus on numbers is largely a distraction - one can argue that, above a certain amount, money does impact the outcome of the presidential race.
To be sure, there is a baseline amount of millions required to pay for the logistics (staff, travel, offices, etc.) of a national campaign. But beyond a certain amount, campaign funds are used to pay for advertising, especially television commercials, which are usually a major campaign expenditure. One commercial outlining Mitt Romney's stance on contraception and abortion rights may fill a gap in a voters's knowledge, but will it change his or her opinion to see the same commercial three more times? Particularly now that the internet allows candidates to gain significant exposure for less, spending on phone banks and TV ads does not bring the return that it once did.
There are also several intangibles that will affect the outcome of the race that cannot be given dollar values. The president will be held accountable for the state of the economy, which is to a certain extent beyond his control, but benefits from the most prominent pulpit in the world. Romney has been able to make campaigning his full-time job, but runs in the shadow of the Bush years. Both candidates are ultimately beholden to their party's base, and no amount of money will change the candidates' records, or our ultimate assessment of their character and fitness to lead.
At the end of the day, the election will turn on several hard realities: The state of the economy, recent foreign policy decisions, the candidates' resumes, and their perception by the electorate. After endless coverage from the news media, voters will largely have made up their minds about the candidates come November. Could any additional amount of campaign spending have convinced you to change your opinion of Sarah Palin? One additional phone call or TV commercial will not make much of a difference at the margin. Fundraising is important, but the candidate with the most money will not necessarily be the next president.