KENNER, La. — Ron Paul, a Republican presidential contender and Texas congressman, said Monday that the Federal Reserve is to blame for the country’s weakening economy. Paul highlighted his economic remedies — abolishing the federal income tax and returning to the gold standard, among them — on a three-city tour of Louisiana. The libertarian-minded Paul was the only candidate to visit Louisiana on the eve of the state’s Republican caucuses Tuesday. The caucuses are an intermediary step in picking a favorite candidate. A presidential primary will take place on Feb. 9 and a state convention will convene on Feb. 16....