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Treasury Secretary Salmon Chase used his post to build a network for his own 1864 presidential run, and his backers circulated the Pomeroy Circular in February 1864 attacking Lincoln's fitness. Lincoln kept Chase in office because his competence at financing the war mattered more than his disloyalty. Months later he appointed Chase Chief Justice, reasoning that Chase would reliably uphold emancipation and the war measures.
In the December 1862 cabinet crisis, Republican senators pushed to oust Seward, partly on information from Chase. Lincoln called a joint meeting where Chase could not repeat his private complaints in front of his colleagues. When both Seward and Chase then offered to resign, Lincoln refused both resignations. Keeping the two opposing factional leaders together meant neither faction could win or walk away, which Lincoln described as riding with a pumpkin balanced in each end of his bag.
Goodwin argues that Lincoln deliberately put his most capable opponents, Seward, Chase and Bates, into key cabinet posts. His reasoning was that the country needed their abilities and the factions they represented. He also made Edwin Stanton Secretary of War, although Stanton had publicly humiliated him in the 1855 reaper case. The approach works only if the leader cares so little about personal slights and credit that the rivals' ambitions can be turned toward the shared goal rather than against him.
When Lincoln was furious, he wrote a blistering letter to its target and then set it aside unsigned and unsent. An example is his rebuke of General Meade for letting Lee's army escape after Gettysburg. Writing the letter released the anger and let him see the case clearly, while not sending it protected a working relationship he still needed. He paired this with publicly taking blame for subordinates' failures, which built a loyalty that criticism would have destroyed.