now. democratic sources say, look the reality is biden would likely only really consider running if she were to stumble in a big way. he has always said publicly he will make the decision at the end of the summer. he is going to take a vacation with his family and talk to his family about it. >> certainly the family man, had ewould certainly consult. looking ahead to tomorrow the president going to a power plant. he's going to make the big announce rmt on the power plant emissions. what has been the reaction in congress? >> reporter: this could potentially be the strongest action taken to combat climate change. but there's a big "if." if it survives there are sure to be a number of challenges. these are tougher versions of proposed regulations first rolled out in 2012 and 2014. according to a senior administration official, the president's going to call for reducing carbon pollution by 32%