Like it or not, history favours Donald Trump being re-elected

If political science and history are guides, Donald Trump will be re-elected president regardless of events during the remaining days of the campaign. Americans almost never eject a party from the White House after only four years and rarely reject a president after one term.

The Republicans, once having gained the presidency, have invariably kept it for at least two consecutive terms since the late 19th century. George H.W. Bush was the only one-term Republican president in well over 100, but he followed immediately after eight years of a fellow Republican in power, Ronald Reagan.

The presidency of Jimmy Carter is the only one in over a century that a party, either the Democrats or Republicans, held the White House for only a single four-year term.

Historically, the Democrats have done best with young candidates: Barack Obama, Bill Clinton and John Kennedy.

They fare less well with older and more established candidates such as Hillary Clinton and John Kerry. Alternatively, Republications enjoy more success with older candidates, such as Reagan.

Presidents running for a second term nearly always gain more votes than during their first successful run for the office. The only exception in modern times is Obama who garnered fewer votes during his second campaign.

History strikingly illustrates how reluctant American voters are to turf a president after a single term. This conservatism stems from three sources: the division of powers in Washington, a term limit and the federal nature of the U.S.

First, unlike elected leaders in many other countries, U.S. presidents are severely constrained in their domestic power notwithstanding the rhetoric of Trump. The president heads the executive or administrative branch of government. That is, the branch responsible for implementing or executing the decisions made by Congress.

In many nations, especially those with parliamentary systems of governance, the head of the executive branch is also the head of the legislative branch. This person — like the Prime Minister of Canada — has both legislative and executive power due to support from one or more political parties in the legislature.

In Washington, presidents must battle the power held by Congress, which itself is split into two bodies, the Senate and the House of Representatives, that are often at odds with each other and in which party discipline is weak. Much of the work of presidents is to find common ground with senators and members of the House of Representatives while avoiding impeachment. The legacy of a peacetime president is based by how successful he was in cajoling Congress to support and fund his proposals and initiatives.

Second, presidents are constrained by the 22nd amendment to the U.S. Constitution passed in 1951 that prevents anyone being elected to the office more than twice. Given this limitation, voters know a second term will be the last one, unlike the situation in countries like Germany where Angela Merkel is in her 15th year of rule.

Third, considerable power is held by the 50 state governments as demonstrated by the diverse responses to the COVID-19 pandemic. As such, any president will regularly encounter formidable organized opposition from large states such as California, New York, Florida and Texas.

The result of the division of powers, the term limit and authority of individual states is that presidents have limited ability to do great long-term harm or immense long-term good. Therefore, it makes sense that Americans at the ballot box feel most comfortable with the adage: better the devil you know than the devil you don’t.