1. Abraham Lincoln – “The Great Centralizer”, Not “The Great Emancipator”. The Emancipation Proclamation did not free the slaves. It offered the promise of freedom to slaves in seven southern states, over which he did not, at the time, have jurisdiction.
2. Theodore Roosevelt – Redefined, no, mis-defined the word monopoly for every generation that has followed.
3. Franklin D. Roosevelt – Socialist. Period.

Under-rated:

1. Calvin Coolidge – Two words: laissez-faire
2. Grover Cleveland – Supported the Gold Standard; opposed Free Silver. Look ‘em up on Wikipedia
3. James Madison – Stretching the definition of underrated a bit, maybe, but he doesn’t get credit for doing so much of the political legwork for Jefferson. He’s thought of as a federalist, because, well, he was. But he became an anti-federalist following the ratification of the constitution, and almost single handedly stopped Hamilton from centralizing the states under federal authority…which would eventually happen under Lincoln, but still…