Vote by Numbers

By Neil deGrasse Tyson

New York Times Op-Ed

It appears that Hillary Clinton is going to suspend her presidential campaign this weekend, at the urging of Democratic Party leaders and superdelegates. Before that happens, Mrs. Clinton and the superdelegates might want to know this: if the general election were held today, Barack Obama would lose to John McCain, while Mr. McCain would lose to Mrs. Clinton.

This conclusion comes not from wishful thinking but from a new method of analysis on the statistics of polls that has been accepted for publication in the journal Mathematical and Computer Modeling. The authors, J. Richard Gott III, a professor at Princeton, and Wes Colley, a researcher at the University of Alabama in Huntsville, are not political scientists. They are astrophysicists. And one of the tasks of scientists is to clarify the apparent complexity of the universe by using the language of mathematics.

Here’s what they discovered: in swing states, the median result of all the polls conducted in the weeks prior to an election is an especially effective predictor of which candidate will win that election—even in states where the polls consistently fall within the margin of error.

This method provides a far more accurate assessment of public opinion than most people’s politically informed commentary. In the 2004 presidential election between John Kerry and George W. Bush, many political analysts said the race was too close to call. But when Professor Gott and Dr. Colley applied the median method in 2004, they correctly predicted the winner in 49 states, missing only Hawaii.

That remarkable success left me wondering what result this method would give if I applied it to the 2008 presidential race. So I examined the past six weeks of polls, taken in 19 important states, that separately pitted Mrs. Clinton against Mr. McCain and Mr. Obama against Mr. McCain. The polls were compiled by and include states like Ohio, Pennsylvania and Florida.

I followed the simple rules established by Professor Gott and Dr. Colley: in states in which a poll has not been taken, you give that state to the party that won it in 2004. You do the same for states where the median poll is a tie.

In 2004, Mr. Kerry won 251 electoral votes, 19 shy of the 270 that would have won him the election. Which states among those that had gone to President Bush would today swing only to Mr. Obama, or only to Mrs. Clinton? And which of Mr. Kerry’s states would swing away from only Mr. Obama or only Mrs. Clinton? All this, of course, is based on current polls.

In Ohio, for example, Mr. McCain beats Mr. Obama two polls to one. But Mrs. Clinton beats Mr. McCain two polls to nothing. So Ohio, which Mr. Kerry did not win in 2004, would go into Mrs. Clinton’s column, giving her an additional 20 electoral votes.

In Florida, Mr. McCain beats Mr. Obama three polls to zero. But Mrs. Clinton shuts out Mr. McCain two to zero. Because Florida went to President Bush four years ago, Mrs. Clinton grabs 27 more electoral votes.

In Michigan, Mr. McCain beats Mr. Obama three polls to zero. But the median poll between Mr. McCain and Mrs. Clinton is a tie. Mr. Kerry won Michigan in 2004, so Mrs. Clinton gets to keep it. But Mr. Obama loses its 17 electoral votes.

When you complete this exercise for each state, Mr. Obama picks up Colorado, Iowa and New Mexico, three states that went Republican in 2004, but he also loses Michigan and New Hampshire, two states that Mr. Kerry had won. Mrs. Clinton loses the previously Democratic states of New Hampshire and Wisconsin, but she would nab 57 electoral votes from the Republicans by winning Florida, New Mexico, Nevada and Ohio.

If the general election were held today, Mr. Obama would win 252 electoral votes as the Democratic nominee, while Mrs. Clinton would win 295. In other words, Barack Obama is losing to John McCain, and Hillary Clinton is beating him.

This analysis does not predict what will happen in November. But it describes the present better than any other known method does.

Poll results can shift, as Mrs. Clinton learned over the past year. The conventions held by both parties usually give candidates a bounce in the polls. Heavy campaigning in close states can swing the sentiments of undecided people. And political gaffes can turn voters away from one candidate and toward another. But these effects would show up monthly in the polls and be duly tracked by this method. The important point is that right now, Mrs. Clinton is ahead of Mr. McCain, and Mr. Obama is behind him.

Two questions arise in the face of this result. Whom should the Republican candidate prefer to run against to maximize his party’s chances of retaining the White House? And what does it say of the Democratic delegate selection system when its winner would lose the presidency if an election were held today, yet its loser would win it?

The median method has gotten us this far. The political analysts need to take it from here.