From 1989 to 2009, for 20 years, there have been two Bush presidencies and one Clinton Presidency.
The framers of the constitution didn't intend for multiple family members to run for president. As had been said recently, the presidency shouldn't be an office passed down from one family member to another. There should be a new constitutional amendment to read:
AMENDMENT XXII
Passed by Congress March 21, 1947. Ratified February 27, 1951.
Section 1.
No person shall be elected to the office of the President more than twice, and no family member of such person who has held the office of President shall be elected to the office of the President.