This is not a fair characterization of what happened in my opinion.She had an agenda. She was trying to argue that being bold with social initiatives was rewarded politically, not dangerous. She was talking about how when the government was at its boldest the democrats won more and were very popular. Her comments came right after how she was blasting her colleagues for arguing that they couldn't do bold things because their district wouldn't go for it.
"When we look at our history, when our party was boldest...we had and carried super majorities in the house and the senate. We carried the presidency. They had to amend the constitution of the united states to make sure Roosevelt did not get reelected."
In my opinion she had zero clue he died in office and thought that they amended the constitution to get him out as like a back door subversion of the will of the american people and this is what ended Roosevelt's presidential tenure. I don't see what else her intent could be interpreted as. What other explanation can be given for her just throwing that random statement into the middle of her argument?
Given the context of what she was saying I don't see how people can say she was mostly correct. Especially when you consider that even Truman could have still run again since he was grandfathered.
Whole segment is
here. Specifics to FDR are around 15 minute mark. The "my district wont go for it" is at about 9:45ish