(Reuters) - President Barack Obama blamed Republicans on Tuesday for contributing to the troubled rollout of his signature healthcare insurance plan and said it will be hard to "rebrand" Obamacare after his administration fixes a website used to sign up for the program. "We should have anticipated that that would create a rockier rollout," Obama told a Wall Street Journal conference."One of the problems we've had is one side of Capitol Hill is invested in failure," Obama said.Obama said he thinks the website will be fixed on time for people to "catch up" and shop for insurance by key deadlines,...