artbrooks -

There were 'third party' candidates in all recent elections. If you ignore that fact you are tampering with the results.

Here are the official results from the last five U.S. presidential elections:

53.37%        George H. W. Bush
43.01% Bill Clinton
49.23% Bill Clinton
47.87% George W. Bush
50.73% George W. Bush

The 43.01% plurality of Clinton in 1992 is the one which stands out as aberrant.