--  A new survey gives President Obama a seven-point lead over Mitt Romney in Minnesota less than a week from Election Day.  The KSTP/SurveyUSA poll shows Obama with 50 percent support, Romney at 43 percent and seven percent undecided.  The president had a ten-point advantage over his Republican challenger in the same survey two weeks ago.  Meanwhile in the latest Star Tribune Minnesota poll, Romney was only three points behind Obama which is within the margin of error.  The SurveyUSA poll also suggests the state's marriage amendment is still too close to call:  48 percent of respondents plan to vote "yes" and 47 percent will vote "no."