Sen. Lindsey Graham is concerned that the Republican Party faces political dangers by resisting efforts to reduce carbon dioxide and other air pollution. That assertion seems to challenge GOP campaigns this year, in which candidates often rejected the science behind climate change. Graham, a Republican from South Carolina, is designing an agenda for next year featuring a clean energy standard for utilities, which rewards increased nuclear and renewable power alike. Similar ideas have failed because they tended to dilute incentives for wind and solar. But under an increasingly conservative Congress, many advocates see that outcome as a potential victory, under reduced expectations.