Why did the conflict between roosevelt and the isolationist grows as the united states prepared for the coming war during ww2

The conflict between Roosevelt and the Isolationists grew prior to World War II as Roosevelt was very blatantly helping the Allied powers with the Lend-Lease Act, which helped get the Americans on a war footing.

Isolationists were opposed to the Lend-Lease Act and this caused a rift.

when world war i broke out across europe in 1914, president woodrow wilson proclaimed the united states would remain neutral, and many americans supported this policy of nonintervention. however, public opinion about neutrality started to change after the sinking of the british ocean liner lusitania by a german u-boat in 1915; almost 2,000 people perished, including 128 americans. along with news of the zimmerman telegram threatening an alliance between germany and mexico, wilson asked congress for a declaration of war against germany. the u.s. officially entered the conflict on april 6, 1917.