Second terms can be tricky.&nbsp; Political winds swing back and forth.&nbsp; The second four years can be difficult.&nbsp; This commentary, written by RedState's Eric Erickson, looks at the Democrats and the challenges they face with their candidate in his second term.&nbsp; <a href="http://www.redstate.com/2013/02/07/the-tipping-point/">www.redstate.com/2013/02/07/the-tipping-point/</a><br />