The correct answer to this open question is the following.
Although there are no options attached, we can answer the following.
I consider that the last "liberal" Republican President was Richard Nixon. Many historians support this opinion based on the decisions he made during his controversial administration.
Nixon tried to maintain foreign trades and political affairs that favored the United States. For instance, Nixon's decision to discontinue the use of the gold standard promoted international investment in the International Monetary Fund.
President Nison got rid of the gold standard on August 15, 1971. To the surprise of many, he announced that the U.S. dollar was not going to be convertible into gold in the foreign markets. When Nixon discontinued the use of the gold standard, international investors invested in different markets and in the International Monetary Fund.
However, everybody knows how Nixon ended up his administration once the Pentagon Papers were published and the Watergate scandal. He had to resign to the presidency in order to not be impeached.
And regarding the first "liberal" Democratic President, I consider it was Franklin D. Roosevelt, the Democrat President that created the New Deal, a series of programs aimed to help the millions of Americans who had lost their jobs after the stock market crash on October 29, 1929, the beginning of the so-called Great Depression.
