Lincoln, then a member of Congress from Illinois, condemned Polk for misleading Congress and the public about the cause of the war — an alleged Mexican incursion into the United States. Accepting the president’s right to attack another country “whenever he shall deem it necessary,” Lincoln observed, would make it impossible to “fix any limit” to his power to make war. Today, one wishes that the country had heeded Lincoln’s warning. ~Eric Foner

One wishes even more that Lincoln could have managed to heed his own warning and not start a war (against other Americans, no less) when he deemed it necessary.  But pay no attention to that–he’s a great President!