Did President Roosevelt consider American public opinion when deciding how to respond to the conflict in Europe?

FDR had to take public opinion into account, because the majority of Americans wanted nothing to do with another war in Europe.  At the same time William Stephensen, a Canadian businessman and head of British Security Coordination acted as a go-between for communications between Churchill (not yet Prime Minister of Britain) and Roosevelt.  These three and William Donovan (who later headed the Office of Strategic Services) covertly set up offices in New York and training areas in Canada to keep an eye on Nazi agents and prepare for eventual war.  This began well before the war actually started in Europe.

The intelligence cooperation between these men and others (such as J. Edgar Hoover and intelligence agencies in other countries) laid the groundwork for the succes of the secret armies built up in Europe from the late 1930s on.  German business conglomerates had deals with hundreds of corporations around the world and owned dozens of subsidiaries globally, all of which were used by German intelligence.  The business contacts of Stephensen and the others enabled BSC to use companies such as International Telephone and Telegraph as intelligence agencies, also.  This cooperation enabled the Western powers to collect contacts, agents and all that was necessary to build up resistance operations in Europe once war began.

The problem for FDR was that all this had to be done secretly, or public opinion would turn against the Allies, or against FDR and a new president less concerned with the looming world war take office.  He had to gradually change opinion in America, and mollify many political opponents of his plans.  The FBI also had to be given credit for successes against espionage networks in America, so the public would not become aware of the British intelligence agency on American soil.  As the war went on the behavior of the Nazi diplomatic corps and occupation troops began to turn public opinion toward a grudging acknowledgement that our country would probably be drawn in.

One casualty was the early civil rights movement, championed by Eleanor Roosevelt.  FDR was forced to shy away from any federal pressure on states with discriminatory laws, lest he lose political support necessary to remain in office and continue the secret war.