On Nov. 6 of last year, the country narrowly voted for a self-described centrist to be president. At the same time, it handed Congress to the Democratic Party in such an exquisitely slender fashion that it would not be clear until the beginning of January whether control of the federal government was to be divided or unified. Once the “moderate” president was sworn in, he and his barely-in-the-majority party proposed restructuring the country from top to bottom, making permanent alterations to the constitutional order if need be. Finally, President Joe Biden has embraced his supporters’ and liberal pundits’ pronouncements that he can and should be “another FDR or LBJ.” To the historically literate, it all should be nothing less than baffling. First of all, Franklin Roosevelt won the 1932 presidential election by 472 electoral votes to 59, while his party won 313 seats in the House and won 58 of the 96 seats in the Senate. Four years later, Roosevelt won the presidency by 523 electoral votes to 8, while his party won 334 seats in the House and 74 seats in the Senate. Lyndon Johnson enjoyed a less protracted period of practical influence, but his numbers were still impressive. In 1964, Johnson won the presidency 486 to 52 electoral votes, and his party won 295 seats in the House and 68 seats in the Senate. Suffice it to say, control of government was clear...