How many republican president that served the term of 8 years?

Nobody has served an eight-year term as U. S. President, but several have served two terms of four years each. These are the Republicans who did so:

1. Ulysses S. Grant (1869-1877)
2. Dwight D. Eisenhower (1953-1961)
3. Ronald Reagan (1981-1989)
4. George W. Bush (2001-2009)

The following Republicans did not complete two full terms but were elected twice:

1. Abraham Lincoln (1860 & 1864)
2. William McKinley (1896 & 1900)
3. Richard Nixon (1968 & 1972)

The following Republicans were re-elected after completing someone else's term:

1. Theodore Roosevelt (1904)
2. Calvin Coolidge (1924)