I have long regarded R.M.Nixon as a RINO but I would NOT saddle him with this exclusivity for starting this trend! FDR, in STEALING the US Citizen's right to own gold (1933) by his confiscation orders, did far more than 'tricky Dick' ever did!
However, insofar as the gold standard, Nixon was in a rock and a hard place. FDR had made ownership of gold bullion by private US citizens illegal. The only exchange of reserve notes for gold was thus by foreign countries. The federal reserve was also printing more reserve notes than we had gold to back them.
Charles D'Galle had the french government exchanging reserve notes for gold, and was encouraging other countries to do the same, which led to a drain of US gold (meaning more reserve notes were backed by an ever decreasing amount of gold).
Nixon basically faced two choices: potential U.S. default, or remove us (and the world) from the gold standard.
Nixon sucked in a lot of ways, but he inherited this problem.
Gold and the dollar diverged, and we had the opportunity (under Reagan, if I recall correctly) where we could've resumed the gold standard, but did not. Since then, we have printed ourselves into oblivion.