Houston Chronicle: Even without their top Republican partner — and with an oil spill in the Gulf of Mexico darkening prospects for success — the chief architects of a climate change and energy bill plan to unveil their measure on Wednesday. The bill, by Sens. John Kerry, D-Mass., and Joseph Lieberman, I-Conn., aims to cut greenhouse gas emissions nationwide 20 percent from 2005 levels by 2020 and 83 percent by 2050, while spurring nuclear power and investing in so-called “clean coal” technology …