William Brangham:

This was the scene today in Oregon's State Senate chamber, once again, much emptier than normal. The body's 11 Republicans didn't show up for work again, after launching a walkout five days ago to stop the state Senate from acting on a contentious climate bill.

That bill would make Oregon just the second state in the nation to put in place a so-called cap-and-trade system to try and limit the carbon emissions that are driving climate change. The state House has already cleared the bill, with strong backing from environmental groups.

But opponents, which include workers in the state's logging industry, rallied at a weekend protest at the state capitol, saying that a cap-and-trade system would hurt certain industries.