[279][280][281][282] Borneman deemed Polk the most effective president prior to the Civil War and noted that Polk expanded the power of the presidency, especially in its power as commander in chief and its oversight over the Executive Branch.[283] Steven G. Calabresi and Christopher S. Yoo, in their history of presidential power, praised Polk's conduct of the Mexican War, "it seems unquestionable that his management of state affairs during this conflict was one of the strongest examples since Jackson of the use of presidential power to direct specifically the conduct of subordinate officers."[284]
Historian John C. Pinheiro, analyzing Polk's impact and legacy, wrote that:[285]

.mw-parser-output .templatequote{overflow:hidden;margin:1em 0;padding:0 40px}.mw-parser-output .templatequote .templatequotecite{line-height:1.5em;text-align:left;padding-left:1.6em;margin-top:0}Polk accomplished nearly everything that he said he wanted to accomplish as President and everything he had promised in his party's platform: acquisition of the Oregon Territory, California, and the Territory of New Mexico; the positive settlement of the Texas border dispute; lower tariff rates; the establishment of a new federal depository system; and the strengthening of the executive office. He masterfully kept open lines of communication with Congress, established the Department of the Interior, built up an administrative press, and conducted himself as a representative of the whole people. 