In the wake of a report that the Obama campaign’s burn rate — the amount of money they are spending per month on the race — has raised concerns among some within the party, the president’s campaign manager insisted that every penny is being well spent.

President Barack Obama speaks at a fundraising event at the Austin Music Hall in Austin, Texas, Tuesday, July 17, 2012. Obama is spending the day fundraising in Texas. (AP Photo/The Daily Texan, Lawrence Peart)

Messina added that the campaign is spending less at this point than George W. Bush spent at the same time in the 2004 campaign despite building a ground game and “currently fending off six or seven Republican super PACs.”

The Obama campaign spent $58 million in June — $38 million of which went to a massive television ad campaign in a handful of swing states. Romney, by contrast, spent $27.5 million in June. That spending disparity allowed Romney to pass Obama in cash on hand at the end of the month; Romney and the Republican National Committee ended June with $170 million in the bank as compared to $144 million for Obama and the Democratic National Committee.

To date, the Obama campaign has spent $107 million on television ads, according to data provided to the Fix by a Republican media buyer. Romney has spent $35 million on ads.

“In terms of ad spending this is the period when voters are learning about Romney’s record and we want to be a part of that conversation, ” said Messina. “In the battleground states as people get to know Romney’s record they like it less and less.”

A NBC-Wall Street Journal poll released earlier this month showed that Romney’s image among voters in swing states had taken a hit, a trend that NBC’s Mark Murray attributed to the Obama ad onslaught.

Wrote Murray:

Romney’s favorability numbers have dropped, possibly reflecting the toll the negative Obama TV advertisements are having on the former Massachusetts governor in these battlegrounds.

Messina’s contention is that “this race at a national level is relatively locked in right now” but that the NBC-WSJ data suggests that the money being spent in swing states to define Romney is already paying dividends.

(Worth noting: Most polling in swing states suggests Obama runs ahead of Romney but that margin is almost always within the poll’s margin of error.)

More broadly, Messina’s self-described “big bet” is that in an election expected to be extremely close — and which almost no one is undecided — that being able to identify and turn out Obama supporters hold the key to winning.

That calculation is similar to how the Bush campaign viewed the 2004 electorate — breaking with the past strategy of targeting independents to instead identify and make sure their own base turned out first and foremost.

Messina and the rest of the Obama team are trying to replicate that Bush approach while simultaneously trying to convince independent/undecided voters that Romney isn’t the candidate for them with a slew of negative TV ads.

That’s an expensive proposition. We’ll know in 106 days whether Messina made the right bet or whether he (and his candidate) went bust.