The Republicans, especially the Goldwater wing of the party, were posing as reformers. What they proposed to change was bloated government that, acting in the name of special interests such as big labor, minorities, and the welfare community, was allegedly taxing average Americans into penury and trampling on their liberties.
Woods, Randall B.. Prisoners of Hope: Lyndon B. Johnson, the Great Society, and the Limits of Liberalism (p. 89). Basic Books. Kindle Edition.
The similarity to Trump is striking – except Trump is more erratic and says all kinds of things. But this is probably what his followers think he is saying.
Hillary was an ardent Goldwater supporter when she was younger – before she met Bill and became part of his team. What she is now – is anyone’s guess.