With Himmler he only had a working relationship at the time of his nomination but, contrary to Speer’s later attempts to distance himself, they formed an alliance and he came to rely on the SS for labor and discipline; by the end of the war they were the “two strong men of the regime”.
Through his work, Speer became well acquainted with the regime’s other important figures. He was already engaging in “office politics” long before being Minister and continued to the end of the war. His decisions were influenced by the need to maneuver around his rivals for control of the war economy: the A4 (V1/V2) program allowed him to sap resources from the Luftwaffe, the development of closer economic relations with France got around Sauckel, the reorganization of the steel industry contested Pleiger and so on. He accumulated “secret sources” of inputs unknown to the other managers of the war economy, which were funneled into his prestige projects. He was very ambitious and in his pursuit of power managed to expand beyond Todt’s fields, which were at first all he controlled, to swallow Kehrl and the navy’s spheres in 1943 and the Luftwaffe’s in 1944.
But he was apolitical in one sense: the propaganda of the arms miracle, in its insistence on the possibility of victory through willpower, did away with questionings of the rationale and purpose of Germany’s position -something Kehrl confronted Speer about but nevertheless lost his power- and thoughts of a political solution to the war, which Generals Thomas and Fromm aswell as Todt had considered.

On the arms miracle itself, Speer’s wartime rhetoric had two elements: the “self-responsibility of industry” and “rationalization”.
In accordance with self-responsibility, or “Selbstverantswortung”, the Ministry would merely set targets for industry to achieve. What this meant in practice is that at least at first there was a close relationship between the regime and the industrialist class, which were bound together by the shared existential threat of a Stalinist victory. In 1942 the industrialists were committed to arming the Wehrmacht to fulfill the Reich’s strategy in the East; the war effort still seemed coherent. Speer sided with the industrialists on matters of business profits, even at the expense of the fight against inflation. The Armaments Ministry’s structure of Rings and Committees was used to communicate with the industry and staffed by companies, each receiving a number of posts proportional to their power.
By 1943 the war effort was losing its coherence and the relationship began to sour. Over the course of the war’s last years the regime’s treatment of industry became dictatorial as the latter’s enthusiasm died off at the same time as the former began to speak of total war and sought a continuous radicalization and mobilization of the economy. Nonetheless “self-responsibility” remained in rhetoric and was used to defend Speer’s methods against the likes of Kehrl, who wanted fiscal tightness and state control.

“Rationalization” was the silver bullet. As the story went, until that point the war economy was held back by bureaucratic inefficiency, which the technocratic Ministry swept away and then, through technocratic reform, began to unleash potentially infinite output from Germany’s limited resources by raising productivity, a triumph of the will that would overcome the enemy’s material superiority. Minute attention to detail would optimize all processes. American-style economies of scale would continually find more productivity. The Minister would empower outsiders to vigorously impose modern techniques against industrial conservatives.
In practice this didn’t matter much. One example of this rationalization was the price system reform initiated a few months before Speer’s nomination, but as shown the previous system was not irrational and the improvement was incremental.