The most recent conservative attack on the Obama campaign has been around the efficacy of its spending, i.e., “they are outspending us on ads, without any movement in the polls.” J.T. Young made this argument in the American Spectator a few days ago, and GOP guru Karl Rove made it today in the Wall Street Journal:

His cash advantage over Mr. Romney was probably gone as of July 31, in large measure because (according to public records at TV stations) Team Obama has spent at least $131 million on television the last three months.

These ads have not moved him up in the polls. The race is tied in the July 30 Gallup poll at 46%. Neither have the ads strengthened public approval of Mr. Obama’s handling of the economy, which is stuck at 44% in the July 22 NBC/WSJ poll, nor have they erased Mr. Romney’s seven-point lead in that poll regarding who has “good ideas for how to improve the economy.”

Rove’s problem is that this goes both ways. When you tally the spending from all groups, Team Romney is outspending Team Obama by a 2 to 1 margin, $14 million to $25 million. As NBC’s First Read points out, this has been true for the last month; overall, in July, the Romney team outspent Obama by more than $20 million.

What has that bought the Romney campaign?

A slightly less negative favorability rating-from a net negative of 5.4 percent, according to the Pollster average, to a net negative of 4.2-and an overall level of support that has yet to budge from 45 percent, the floor for a major party nominee. The picture is even worse when looking at swing states; in Florida, Ohio, Virginia, Colorado and Nevada, Obama has a consistent lead. As I noted yesterday, this implies a slightly larger national advantage than what we see in the polls.

Yes, Karl Rove is the definition of a hack-so it’s no surprise that he would spin the picture in favor of Romney-but it’s important to note the degree to which his point matters much more for Romney than it does Obama.

In general, it’s difficult for challengers to break through status quo bias and attract a critical number of undecided voters. For Romney in particular, he’s still vulnerable to attacks on his qualifications and persona, as we saw over the last month with the constant criticism of his tax returns and record at Bain Capital. This will only continue, and it has the potential to worsen Romney’s poor ratings with the public. If, by October, Romney is still outspending Obama with little change in his favorability numbers or amount of support, we’ll look back to now and say that he was the one who peaked.