The democrats are split and half of them are against Joe Biden. If Sanders people were to call for Hunter to be investigated, that would be half the democrats and all the republicans, or about 75% of the country. If they did it in earnest and the deep state still protected Joe and "found no wrong-doing", then they'd see how we feel about rigged investigations and they would never vote for Joe no matter what. Many would defect to vote Trump out of spite. The rest would stay home. If they DID investigate and indict Joe, Trump has a layup against an old socialist.