Because the US is not a democracy. It is democratically elected republic. And even that is debatable due to large populations in a few key states.
It is possible to win the election by winning eleven states and disregarding the rest of the country. If one were to take California (55 votes), Texas
(34), New York (31), Florida (27), Illinois (21), Pennsylvania (21), Ohio (20), Michigan (17), Georgia (15), New Jersey (15), and North Carolina (15),
that ticket would have 271 votes, which would be enough to win regardless how the rest of the country votes.
That is of course relating to just the presidency.
As for both the House and the Senate fortune favors the incumbent by name recognition. Of course this can and is tipped by overwhelming campaign
spending so uninformed voters may vote for the more familiar name. Of course blind party affiliation voting also comes into play. This is how some
politicians remain seated their entire political lives like Ted Kennedy for example despite a problem of alcoholism for many years.

