Clearly discerning Van Buren as his most formidable competitor for political leadership, Clinton's letters to Post from 1817 to 1824 abound in vituperative allusions, as, for example: "Whom shall we appoint to defeat the arch scoundrel Van Buren?" November 30, 1820. "Of his cowardice there can be no doubt. He is lowering daily in public opinion, and is emphatically a corrupt scoundrel," August 30, 1820. "Van Buren is now excessively hated out of the State as well as in it. There is no doubt of a corrupt sale of the vote of the State, although it cannot be proved in a court of justice," August 6, 1824. "We can place no reliance upon the goodwill of Van Buren. In his politics he is a confirmed knave." And again: "With respect to Van Buren, there is no developing the man. He is a scoundrel of the first magnitude, ... without any fixture of principle or really of virtue." "Van Buren must be conquered through his fears. He has no heart, no sincerity."] Like many other brilliant political leaders, Van Buren was somewhat thin-skinned; he happened, too, to be out of the State Senate, and thus was compelled to endure, in silence, the attacks of the opposition. It is believed that at this time, Van Buren had a strong inclination to accept a Supreme Court judgeship, and thus withdraw forever from political life. But the fates denied him any chance of making this serious anti-climax in his great political career. While the green bag message convulsed the Clintonians with simulated indignation, the Bucktails declared him, by a caucus vote of fifty-eight to twenty-four, their choice for United States senator in place of Nathan Sanford, whose term expired on March 4, 1821.