The climate bill passed by the House last week now goes to the Senate, where capping greenhouse emissions could face a rougher ride.

   Its fate could depend upon a group of about 15 moderate Democrats who have generally staked out a middle ground on President Obama’s domestic agenda.

    One of them, Missouri Sen. Claire McCaskill, said on Twitter over the weekend: “I hope we can fix cap and trade so it doesn't unfairly punish businesses and families in coal dependent states like Missouri.”