From “New Rove Group Could Backfire on G.O.P., Nate Silver, FiveThirtyEight, NYT:
“Mr. Rove’s efforts could back fire, therefore, if they result in the insurgent candidate receiving more sympathetic treatment through these channels [conservative-friendly news media outlets]; the amount of so-called ‘earned media’ that the insurgent receives could outweigh the extra advertisements that the establishment candidate is able to afford.
“My analysis of fund-raising data…has found that it is generally the proportion or ratio of funds raised by each candidate that has the most power to predict races, rather than the absolute amounts.
“Suppose, for example, that the establishment candidate has raised $3 million and the insurgent candidate $500,000, a six-to-one advantage for the establishment candidate. Mr. Rove’s group intervenes and contributes $1 million to the establishment candidate, bringing him to $4 million total. In response, the insurgent candidate raises $500,000 through grass roots groups, bringing her to $1 million total. Despite the absolute difference between the candidates’ fund-raising totals having increased, the ratio has declined to a four-to-one advantage for the establishment candidate from six-to-one previously, arguably leaving the insurgent candidate in better shape than before the fund-raising salvos.”