Though many would argue with you about who is 'qualified' and who isn't.
We're talking about the Presidency of the United States of America. The Chief Executive Office of the country. We have almost always in the last 100 years elected candidates who have had significant EXECUTIVE experience in government, typically found in either serving as governor of a state or as vice president. This was true of GW Bush, Bill Clinton, GHW Bush, Reagan, Carter, Ford, Nixon, Johnson, Truman, Roosevelt. The anomalies are Eisenhower, who served as supreme commander of all Allied armed forces during World War II, and Kennedy with 16 years experience in Congress.
The election of 2008 was anomalous in that none of the 4 candidates had executive experience except for the Republican vice presidential candidate, whose experience was minor. In 2016 the only one of the 4 candidates on the 2 major tickets who had ANY executive experience in government was Pence.
This year on the Republican ticket you have a presidential candidate with 4 years experience serving as president and a vice presidential candidate with 4 years experience serving as vice president in addition to his service as governor of Indiana.
On the Democrat ticket? A former vice president with dementia.