Former President Barack Obama on Friday warned Democratic primary candidates to avoid leaning too far left in their campaigns, and raised concerns that certain liberal policy proposals on health care and immigration might have gone further than public opinion. In an unusual address to a room of wealthy Democratic donors, Obama urged Democratic candidates to be pragmatic in their messages to voters. While he didn’t mention any specific presidential primary candidate or proposal, Obama warned that the average American voter does not align with views from “certain left-leaning Twitter feeds or the activist wing of our party.” Obama said that...