The Republican-controlled House impeached President Clinton, and most Republicans in the Senate seem eager to throw him out, despite polls showing that Americans overwhelmingly do not want this to happen. It is unusual for politicians of either party to go against such a clear expression of the popular will. Are pro-impeachment pols courageously acting on their own deeply held convictions, irrespective of the political consequences? Or is there some more plausible explanation?
There are two such explanations. One is that the politics of individual districts is different from that of the country as a whole. The other is that, to get elected, a politician must win the party primary as well as the general election.
In a constituency system like the U.S. Congress, it is theoretically possible for every representative to follow the wishes of the majority in her district and nevertheless produce a result that is against the wishes of the majority of all voters.
Example: Suppose there are 10 congressional districts of 10 voters each. In four districts, all ten voters are against impeachment. In the other six districts, four voters are anti-impeachment and six are pro. A referendum would show that 36 voters support impeachment while 64 oppose it. But if Congress members obey the majority in their individual districts, then six will vote for impeachment and four will vote against.
Professor Morris Fiorina of Stanford University estimates that 180 of the 228 Republican Congressional districts favor impeachment. Assuming that none of the Democratic districts favors impeachment, that means 180 out of 435, or 41 percent, of all congressional districts have a pro-impeachment majority. Among voters generally, only 33 percent or so approve of Clinton's impeachment. So the constituency effect created more districts with a pro-impeachment majority than the pro-impeachment share of voters generally. But even if 41 percent of all members of Congress were just slavishly following the wishes of their own voters in supporting impeachment, what about the other 11 percent? (Fifty-two percent of the House voted for impeachment.)
That's where the primary effect comes in. Winning the primary means appealing to the members of one's own party. Not only is the average Republican to the right of the average voter (just as the average Democrat is to the left), but the average Republican primary voter is further right still. And party activists (of both parties), who are needed to give money and help in the campaign, tend to be even more extreme.
Politicians usually try to shift emphasis--if not make entirely different sets of promises--between the primary and the general election. But it is hard to shade or slice'n'dice impeachment: You're either for it or against it. (Four Republican congressmen are already feeling the wrath of voters after announcing the other day that they weren't in favor of removing Clinton from office even though they had voted for an impeachment resolution calling for just that.) Fear of a primary challenge could cause a member of Congress to vote for impeachment even if a majority of voters in her district opposed it. And added to the constituency factor, this could explain why a majority of Congress voted for impeachment--against the wishes of a majority of voters--without resort to the terrifying possibility they were acting on principle.
Explainer also thanks Professor Edward Schwartz of Harvard University.