George W. Bush began his administration with a promise to “change the tone” in Washington only to end it with a lament over his inability to do so (unless, some argue, he made it worse). Bill Clinton began his second term by calling a halt to “acrimony and division” and then generated buckets of the stuff over the next four years (low-lighted by his own impeachment).
The first sentence suggests that it is a matter of dispute whether Bush, the most polarizing president in American history, increased partisanship and division in Washington. By contrast, Leibovich asserts that Clinton "generated buckets of [acrimony and division]", including his impeachment, without even mentioning the conservatives who tried to delegitimize and destroy his presidency from his first days in office. While Clinton surely deserves some blame, particularly for his affair with Monica Lewinsky, it's hard to see him as the prime mover behind the "acrimony and division" of his second term in office.
PS Contrary to Leibovich's implication, Bush's goal of "changing the tone" was hardly benign. As we argue in All the President's Spin, the phrase was used as a way to implicitly delegitimize dissent, particularly after Sept. 11.