"We’re going to spend tens of millions in this period, when the campaign and the party committees aren’t fully ready to take over."

—Tim Phillips, president of Koch-backed nonprofit Americans For Prosperity, on the group’s big new ad campaign attacking Obama’s green energy policies.

As the Los Angeles Times' Matea Gold and Melanie Mason report, outside groups such as Americans For Prosperity and Crossroads GPS — both nonprofit “social welfare” organizations that are not required to reveal their donors — are pouring millions of dollars into attack ads hitting President Barack Obama before the general election gets in full swing.

Another article by Bloomberg’s Heidi Przybyla highlights the outside groups’ energy agenda: 

In April, 16,991 negative ads aired in various parts of the country and 13,748 of them — or 81 percent — focused on energy, according to data provided by New York-based Kantar Media’s CMAG, which tracks advertising.

Republicans say the ads are timely and effective because high gasoline prices put Obama on defense at the onset of the general election. Democrats say they prove that Republicans are struggling to find an effective attack line amid an economy that is showing signs of recovery.

The outside spending is set to intensify from here: The Los Angeles Times reports that Americans for Prosperity plans to pour $151 million into TV and on-the-ground operations aimed at the 2012 election, with 80% of its TV budget to be spent before Labor Day.