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After the house impeaches a president, the Constitution requires a two-thirds majority in the Senate to remove him from office. Opponents of impeachment point out that, despite the greater severity of the prospective charges against Trump, there is little reason to believe the Senate is more likely to remove him than it was to remove Clinton. Indeed, the Senate's Republican majority has shown little will to break with the president—though that may change. The process of impeachment itself is likely to shift public opinion, both by highlighting what's already known and by bringing new evidence to light. If Trump's support among Republican voters erodes, his support in the Senate may do the same. One lesson of Richard Nixon's impeachment is that when legislators conclude a presidency is doomed, they can switch allegiances in the blink of an eye.
But this sort of vote-counting, in any case, misunderstands the point of impeachment. The question of whether impeachment is justified should not be confused with the question of whether it is likely to succeed in removing a president from office. The country will benefit greatly regardless of how the Senate ultimately votes. Even if the impeachment of Donald Trump fails to produce a conviction in the Senate, it can safeguard the constitutional order from a president who seeks to undermine it. The protections of the process alone are formidable. They come in five distinct forms.
The first is that once an impeachment inquiry begins, the president loses control of the public conversation. Andrew Johnson, Richard Nixon, and Bill Clinton each discovered this, much to their chagrin. Johnson, the irascible Tennessee Democrat who succeeded to the presidency in 1865 upon the assassination of Abraham Lincoln, quickly found himself at odds with the Republican Congress. He shattered precedents by delivering a series of inflammatory addresses that dominated the headlines and forced his opponents into a reactive posture. The launching of impeachment inquiries changed that. Day after day, Congress held hearings. Day after day, newspapers splashed the proceedings across their front pages. Instead of focusing on Johnson's fearmongering, the press turned its attention to the president's missteps, to the infighting within his administration, and to all the things that congressional investigators believed he had done wrong.
It isn't just the coverage that changes. When presidents face the prospect of impeachment, they tend to discover a previously unsuspected capacity for restraint and compromise, at least in public. They know that their words can be used against them, so they fume in private. Johnson's calls for the hanging of his political opponents yielded quickly to promises to defer to their judgment on the key questions of the day. Nixon raged to his aides, but tried to show a different face to the country. "Dignity, command, faith, head high, no fear, build a new spirit," he told himself. Clinton sent bare-knuckled proxies to the television-news shows, but he and his staff chose their own words carefully.
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