On September 25, 2013, the Kindle Fire HD was upgraded as the third generation Fire, priced at US$139, and the Kindle Fire HDX was introduced. The Kindle Fire HDX had an improved graphics engine, double the memory, and triple the processor speed of the previous model.
Washington, wary of the dangers posed by an individual's becoming entrenched in the presidency, created a two-term tradition that remained intact until Franklin Delano Roosevelt's third consecutive election in 1940.
In 1936, he won his second term in office by defeating Kansas governor Alf Landon in a landslide. On July 18, 1940, Roosevelt was nominated for a third presidential term at the Democratic Party convention in Chicago. The president received some criticism for running again because there was an unwritten rule in American politics that no U.S. president should serve more than two terms.