Sarah Palin on Tuesday joined a growing chorus of Republicans calling for the impeachment of President Obama, writing in a Breitbart op-ed that the influx of young illegal immigrants over the southern border "is the last straw that makes the battered wife say, 'no mas.' " Mixed/careless metaphors aside, this is nothing but bad news for Republicans — especially four months until the 2014 election. Palin is hardly the first GOP politician to raise the issue of impeachment over the past couple years. Others include Sens. James Inhofe (R-Okla.), Tom Coburn (R-Okla.) and Tim Scott (R-S.C.), Reps. Blake Farenthold (R-Tex.),...