The White House contends that all energy loan guarantees, including the more than $500 million given to now-bankrupt solar firm Solyndra, are awarded solely on the merits of the project, with no political influence from President Obama, Vice President Joseph R. Biden or other administration officials.

But a series of emails from solar power giant BrightSource Energy Inc. show how the company applied political pressure and used behind-the-scenes cajoling to win a $1.6 billion loan guarantee in April 2011.

And the beat goes on......