The Senate narrowly confirmed Kevin Warsh chair of the Federal Reserve, setting up the most controversial leadership transition at the US central bank in decades and a test of its political independence.  The 54-45 vote Wednesday was the slimmest confirmation margin ever for a head of the central bank, reflecting polarized politics in Congress and Democratic fears that Warsh will bend to President Donald Trump’s demands to rapidly lower interest rates.Bloomberg's Mike McKee joins Bloomberg Businessweek Daily to break down the confirmation.