By Investopedia.com

If President Donald Trump is not re-elected, he would be the first president since George Bush Sr. to not secure a second term. Below is a list of the last five presidents who lost re-election, from the earliest U.S. leader to most recent, and the reasons why they came up short.

William Taft

President William Taft served as the 27th President of the U.S. between 1909 and 1913. He struggled to fill the shoes of Theodore Roosevelt, one of the most popular presidents in the 20th century. It was Roosevelt's friendship and support that helped Taft win election in 1908. However, his relationship with Roosevelt soured while Taft was in office, and Roosevelt ran as a third party candidate in the 1912 election, drawing votes away from Taft. Taft was defeated by President Woodrow Wilson.

Herbert Hoover

President Herbert Hoover was the 31st President and served between 1929 and 1933. The stock market crash of 1929 occurred immediately after Hoover entered office, leading to the Great Depression. Blamed for these events, and his failure to stem the economic and financial losses, he was defeated in the 1932 election by Franklin Roosevelt, the only U.S. president to be elected to more than two terms.

Gerald Ford

President Gerald Ford served as the 38th president of the United States. Ford came to the presidency as the only person never to be elected Vice President or President. He became Vice President under the 25th Amendment when President Richard Nixon's Vice President, Spiro Agnew, resigned in disgrace. Ford was appointed Vice President by Nixon and confirmed by congress. As the Watergate scandal escalated, Ford became President after Nixon also subsequently resigned, the first U.S. President in American history to do so. Ford then pardoned Nixon of all crimes committed while in office, an enormously unpopular decision. His chances of reelection were further undermined by a combination of low economic growth and inflation, known as stagflation. In 1976, he was defeated by Jimmy Carter.

Jimmy Carter

President Jimmy Carter was the 39th U.S. president, elected in 1976, and serving from 1977 to 1981. During his presidency, the U.S. continued to suffer from stagflation. This was compounded by the unsuccessful rescue of U.S. hostages in Iran near the end of his term. These factors led to his defeat by Ronald Reagan in the 1980 election. President Carter has had an unusually active post-presidential career, during which he has promoted peace efforts and diplomacy around the world, for which he was awarded the 2002 Nobel Peace Prize.

George Bush, Sr.

President George H.W. Bush, the 41st U.S. president, is also known as Bush Sr. to differentiate him from his son, George W. Bush, who won the presidency in 2000, and again in 2004. Bush Sr. was elected in the fall of 1988 and served between 1989 and 1993. During his presidency, he oversaw the U.S.-led first Gulf War that ended Iraqi occupation of Kuwait. While the military campaign was a success, President Bush's popularity suffered as the economy faltered later in his term. In 1992 he lost his re-election bid to Bill Clinton.