Democrats didn't investigate Trump over Russia. REPUBLICANS investigated Trump over Russia
Jeff Sessions, Trump's DOJ appointed Robert Mueller, a life-long Republican and former Director of the FBI, as special prosecutor after Trump went on CBS and said he fired Jim Comey over the Russia Investigation.
Trump's confession on national television lead to the Russia Investigation. When a republican is in the White House, all department of justice investigations and prosecutions are carried out by the Republican department of justice
Before you start calling other people “idiots” you should remember the Bush 41 was President, during the first Gulf War when Iraq attacked Kuwait.
You could save yourself a lot of humiliation, if you would just simply fact check your posts before you make an idiot of YOURSELF.