Senator John Barrasso (R-WY) led a May 23 letter urging President Obama to approve the Keystone XL pipeline without creating additional environmental policies like a carbon tax, fuel standards, or power plant emissions standards. The letter, cosigned by 23 Senate Republicans, cited Democratic proposals to issue climate change regulations concurrently with the pipeline approval. The same day, citing climate change and economic issues, Representative Raul Grijalva (D-AZ) was joined by 30 of his House Democratic colleagues in sending a letter urging the president to oppose the Keystone XL pipeline.