Both leading Democrat and Republican candidates vie to show they can tackle global warming.
Growing divisions among pro-US Sunni tribal chiefs threatens to unravel American gains against Al Qaeda.
His victories Tuesday make eight in a row and show he's eroding Clinton's core constituencies.
House Democrats consider an ethics board, and Republicans adopt reform standards.
In agreeing to stop the post-'surge' drawdown in Iraq, Defense secretary keeps pressure on the service.
Kirk Johnson is devoted to helping Iraqis resettle in the US. Hundreds, faced with death threats, are still waiting.