Why have most presidents since 1900 been governors or senators?

Because at that time, we still do not have technology such as Television and social media.
Because of this, the only way for us to obtain political influence and favorability among the people (which is needed to become a president) is by first making connection in lower office such as Governors or senators.

Yes you are cute answer theories to explain the colonization of the new world the last great habitable landmass to be occupied by humans focus on the bering land bridge, or beringia, which emerge by siberia and alaska the last ice age.

Answer:

american political culture includes a plenty of focus views and preferences. not all westerns experience the same opinions, of course, but the large preponderance promises to these general ideas, including equality, justice, freedom, individualism, integrity, and difference.

explanation:

the united states is a democratic republic. residents elect representatives to governmental, nation, and local administration; those deputies create the regulations that command u.s. community. although emptiness in u.s. law needs it, in usage, the administrative system is ruled by executive factions.