Except Democrats have been consistently beating Republicans in presidential elections. Click the links. Go back further if you want to. The Republican candidate has won the popular vote exactly once (in 2004) since 1990.
The Presidential election popular vote margin has not gone over 10 million votes in over three decades now, in a country that has averaged about 300 million residents over that time span. These are not margins that support the idea that the population as a whole skews left as much as mainstream media skews left.