In spite of his defeats and humiliations, Johnson remained determined to fight on until he achieved victory and vindication, just as he had done in his struggle against secession. He believed that although most northerners, duped by Republican propaganda, might agree to civil rights for blacks, they would not support the imposition of black suffrage on their fellow whites of the South or the indefinite prolongation of bayonet rule in the southern states. Sooner or later, he calculated, the Republicans would "hang themselves" with their extreme measures as public opinion in the North turned against them. Meanwhile, until that happened, and in order to help make it happen, he would do everything he could to oppose, cripple, and discredit Military Reconstruction. He also hoped, indeed expected, that the Supreme Court would declare the congressional program unconstitutional. Already, on 17 December 1866, the Court had held in the case of Ex parte Milligan that military tribunals had no right to try civilians in areas where the civil courts were functioning—a decision that obviously had negative implications for the Military Reconstruction Act.
On 1 April 1867 an election in Connecticut resulted in the Democrats capturing the governorship and three of that state's four congressional seats—the first Democratic victory in the North since 1864. Johnson saw this as a "turn of the current" of northern public opinion. It also encouraged him to launch an indirect but potentially devastating assault on Military Reconstruction. At Johnson's behest, Attorney General Henry B. Stanbery prepared an interpretation of the legal powers of the district commanders in the South that, in the words of Michael Les Benedict, "virtually emasculated the Reconstruction law." The Republicans, who had anticipated such a move, quickly reconvened Congress, which on 13 July passed a supplementary Reconstruction bill that overruled Stanbery's interpretation on every important point. Automatically Johnson vetoed the bill, and just as automatically, Congress repassed it over his veto and then again went home, hoping that Johnson finally realized the futility of resisting its will—a vain hope.
Playing a key role in carrying out Military Reconstruction was Secretary of War Stanton. For a long time Johnson had been aware of the fact that Stanton constantly obstructed his policies, that he habitually lied to him, and that he was actively aiding the congressional Republicans. Yet he had held back from dismissing him from the cabinet out of fear of the political and personal repercussions, for Stanton enjoyed great prestige in the North because of his wartime services and possessed strong backing among the Republicans. By the summer of 1867, Johnson had decided that he no longer would tolerate Stanton's disloyalty to his administration. Therefore, on 11 August, after failing to obtain Stanton's resignation, he suspended Stanton from office under the terms of the Tenure of Office Act and named Grant acting secretary of war, a post Grant accepted with great reluctance, as he, too, opposed the president's Reconstruction program and had been secretly collaborating with Congress. In addition, on 17 August, Johnson relieved Major General Philip H. Sheridan as commander of the Military District of Louisiana and Texas, where he had been pursuing a course that Johnson deemed both tyrannical and insubordinate.
As was to be expected, the Republicans reacted to Stanton's suspension and Sheridan's removal with anger and demands for impeachment. Johnson was unmoved, and the outcome of the autumn state elections reinforced his feeling that northern public opinion was shifting in his favor. The Democrats won in New York, New Jersey, and California; gained control of the Ohio legislature; and sharply reduced Republican majorities in several other states. In addition, the voters of Ohio, Minnesota, New Jersey, and Kansas overwhelmingly rejected black suffrage in their states. Unlike in 1866, when most Republican candidates carefully avoided the issue, in 1867 they came out in favor of granting blacks the vote in the North as well as the South. The result was that, in the blunt words of Radical Senator Benjamin Wade, "The nigger whipped us."
When Congress convened in December 1867, Johnson announced to his cabinet, "The time for mere defense is now past and I can stand on the offensive
Infuriated, the Radicals called for the House to impeach Johnson. But the Moderates, although likewise angry, stated that unfortunately there was no legal basis for such action, and after an acrimonious debate the House on 7 December defeated an impeachment resolution by 108 to 57, with 66 Republicans joining 42 Democrats in opposition. Radical leaders thereupon began deploring the "surrender of Congress" to the president, whereas one of John-son's confidants asserted that "the President has Congress on the hip." Further encouraging Johnson while at the same time alarming all Republicans, the case of Ex parte McCardle , involving the constitutionality of the Military Reconstruction Act, was now before the Supreme Court; on the basis of the Milligan precedent, the Court would almost surely strike down the act.
But if Radicals and Moderates differed as to the feasibility of impeaching Johnson, they did agree that he must not be allowed to displace Stanton permanently as secretary of war. If that happened, the Tenure of Office Act would become a dead letter and Johnson would be free to name a secretary of war who would cooperate with him in sabotaging Military Reconstruction, thereby threatening Republican domination in the South. Hence, on 13 January 1868 the Senate, applying the Tenure Act, rejected a request from Johnson that it concur in Stanton's dismissal and declared that Stanton was still secretary of war.
Johnson had anticipated this action. Accordingly he had asked Grant not to surrender the secretary of war's office without giving prior notice; in this way Johnson would have an opportunity to appoint someone else to the post so as to bring about a Supreme Court test of the Tenure Act. Grant promised, or at least permitted Johnson to understand that he promised, to do what the president requested. But on 14 January, after the Senate refused to sanction Stanton's removal, Grant went directly to the War Department building, locked the secretary of war's office, and turned over the key to a military aide; an hour later Stanton arrived, obtained the key, and entered his old office.
Johnson accused Grant of "duplicity" both before the cabinet and in the press. Grant heatedly denied the charge and thus the two became open, bitter enemies. Probably Grant did betray Johnson, for although he had warned Johnson that he would quit as acting secretary of war if the Senate rejected Stanton's dismissal, he knew that the president did not expect him to do it so abruptly and in a manner that would make it so easy for Stanton to regain physical possession of the office. On the other hand, Johnson was seeking to exploit for his own purposes Grant's prestige and popularity; and had Grant allowed him to do this, Grant would have been caught in the middle of the struggle between the president and Congress. Realizing this, Grant decided to extricate himself, even though it meant acting in a fashion that at best can be described as slippery.
Foiled in his plan to prevent Stanton from taking possession of the war office, Johnson next tried to force him out of it, his intention still being to bring about a legal test of the Tenure Act. To this end, on 21 February he appointed the adjutant general of the army, Lorenzo P. Thomas, secretary of war and instructed him to go to the War Department and demand that Stanton vacate the office. Thomas, an elderly, ineffectual type, did so twice; each time Stanton adamantly refused and Thomas went away.
The Republicans exploded with anger and joy—anger because Johnson was so brazenly defying the will of Congress and joy because he had at last given them a plausible reason to impeach and remove him from office. On 24 February the House of Representatives, by a vote of 126 to 47, passed a resolution declaring "that Andrew Johnson, President of the United States, be impeached of high crimes and misdemeanors." For the first time in American history a president had been impeached.