You ought to believe certain groups of people have more investment acumen than others.
And as the study in this The Christian Science Monitor article concludes, the US Senators is one of such groups. "The study found that during the boom years of 1993-98, a majority of US Senators were trading stocks - and beating the market by 12 percentage points a year on average. By comparison, corporate insiders beat the market by 5 percent, and typical households underperformed by 1.4 percent." I cannot judge whether they have more information, or more intelligence than others.
Source: Tax Guru-Ker$tetter Letter