Ben Carson, Marco Rubio and Rick Perry (now supporting Ted Cruz) have all faced the age-of-earth controversy. Politicians have engaged the old earth/new earth issue, but what about the power struggles and sociology of science that has led to a 4.5B year old planet?
Around 1900 there was a wide range of estimates for the earth’s age that were seriously considered. Hermann von Helmholtz gave a date of 22M years based on the sun’s loss of energy. By 1931 Arthur Holmes used the results of radiometric dating to assert that this planet is at least 1.5B years in age. 
In 1883, Alexander Winchell, former State Geologist of Michigan, estimated that the age of the earth at 3M years. Former president of the Geological Society of London, Andrew Ramsay (d. 1891), held that the earth may be 10B years old! 
Arthur Holmes, the most important person to make radiometric methods the dominant dating method, said in 1913, “It is now well known that if the proportion of radium in the interior of the earth is the same as that in the surface rocks, the earth ought to be growing hotter…”  Did Holmes abandon his old earth PreSuppositions because of this contrary evidence? No, he held tenaciously to his Deep Time WorldView.
In 1921, at a meeting of the British Association for the Advancement of Science, there was no consensus on radiometric dating and an Earth that’s billions of years old. In 1926, a committee of the National Research Council concluded that radiometric dating was the only reliable method to date rocks. Arthur Holmes, who led the campaign for radiometric dating, wrote 70% of the report. What in the politics of science changed between 1921 and 1926? Scott Frickel and Kelly Moore have edited The New Political Sociology of Science (Univ. of Wisconsin Press) which tackles the power struggles in the research establishment.
To learn more about this drama in science, be sure to get your copy of YES - Young Earth Science today! Chapter Two deals with the history of radiometric dating. This fully documented work has over 450 footnotes and more than 130 charts, graphs and illustrations.
1) YES - Young Earth Science by Jay Hall (IDEAS, Big Spring, TX, 2014), p. 17.
2) Ibid., p. 50.
3) quoted in Hall, p. 40
M=million, B=billion (10^9)