Two different things here
Do I believe that Russia actually interfered in the election (changed results, tampered with voting machines, changed voter rolls) the answer is NO
Do I believe Russia ran social media campaigns to spread misinformation and screw the American peoples perception of candidates then the answer is YES
But heck we do that to mess with other countries all the time
Right now we are talking about military intervention in Venezuela to impose our will in that country. We have done that in many countries around the world for decades. Since we are the good guys its OK when we do it