“Obama: The most polarizing president. Ever.”

That was the headline on a January 30 blog post on The Fix, the Post’s very popular politics blog, by reporters Chris Cillizza and Aaron Blake. The post was based on a Gallup study of the average gap between poll respondents in each party who approve of how a president is doing his job in any given year.

It’s a great headline. It’s brief, punchy, says something that a lot of people in the political world talk about. And I’m sure it drove tons of traffic to The Post’s Web site.

But readers wrote to me saying it was at worst wrong, and at best misleading.

As the readers, and the Gallup study pointed out, George W. Bush had the three most polarized years ever in presidential history by this measurement, his fourth, fifth, and sixth years, when the gap between Republicans and Democrats who approved of the way he handled his job was 76 percent, 72 percent, and 70 percent respectively. Obama’s highest mark so far is 68 percent.

Some of the readers who wrote were obviously fans of President Obama, but others were fans of accuracy.

Dan Hamrick wrote this to me: “It took brazen dishonesty for The Washington Post and its Chris Cillizza to define Barack Obama as ‘the most polarizing president ever.’ Few, if any presidents, ever have bent over so far to kiss the feet of Congress, only to have them rebuff him at every turn. Why not, ‘Congress most polarizing ever during Obama administration.’ That would be half-way to the truth.”

Jim McBride of Falls Church was so upset that he wrote to me twice:

“I have observed a careless interest in serious journalism by The Fix for awhile now and today’s headline ranks as one of the most misleading headlines I can remember. It shows clearly in the article that George W. Bush was the most polarizing president ever with three years ranking as more partisan than any year of President Obama. Please post a correction and ensure that The Fix raise its standards.”

In his second e-mail, McBride made suggestions. The original headline could have been accurate with a simple question mark placed at the end, “Ever?” Or it could have said, “Obama: Most polarizing start. Ever.”

Gallup didn’t use the construction that Obama, or Bush, was the most polarizing. Its headline said, “Obama’s approval ratings more polarized in Year 2 than Year 1.”

For Jan. 20, 2010, through Jan. 19, 2011, Obama’s second full year in office, “an average of 81 percent of Democrats and 13 percent of Republicans approved of the job Obama was doing as president . . . That 68-point gap in party ratings is up from 65 points in his first year and is easily the most polarized second year for a president since Dwight Eisenhower,” when the gap was only 37 percentage points.

Cillizza also added in the data for Obama’s third year, for 2011, when an average of 80 percent of Democrats approved of the job he was doing in Gallup polls, as compared with 12 percent of Republicans who felt the same way. Still a 68-point gap.

Notice that Gallup never said that the president is polarizing, only that the respondents are polarized during a particular year of the presidency.

Gallup also pointed out that, “In total, [George W.] Bush accounts for six of the 10 most polarized presidential years in Gallup history. Bush’s first two years were less polarized owing to the rally in support he got from Americans after the Sept. 11, 2001, terrorist attacks. Clinton and Reagan are the only other presidents to make the top 10 list; both did so in the year they were re-elected.”

No one disputes that the country is more polarized than it used to be, and has been since Reagan. But no one really knows the cause of it. Using “polarizing” in this headline makes it seem like Obama is the cause of it. It could be President Obama, sure. It could be Republicans, racism, the sour economy, Congress, Fox News or MSNBC, The Post, or a combination. No one really has done a good study of what contributes to polarization.

Yes, if you’re going to use the “polarizing” construction correctly, the approval gap was widest under President George W. Bush in his fourth, fifth, and sixth years in office. But Cillizza and Blake are right that looking at the first three years in office, Obama wins, his first three years having been more polarized than in any other president’s.

Cillizza explained the headline in an e-mail. “The reason for the headline — from my vantage point — was that the first three years — 2009, 2010, and 2011 — of the Obama presidency had featured the largest partisan gaps in presidential approval ratings between the two parties than any first three years of any president since Gallup started measuring it back in 1953. I suppose I could have headlined it ‘Obama's first three years in office were the most polarizing’ — my intent was not to mislead but rather to make the same point in less words.”

And Cillizza points out that ‘polarizing’ need not be pejorative. “The numbers are the numbers — people add the meaning they like to them. Part of the reasons for Obama’s polarization — as I point out in the piece — is that his numbers among Democrats are so strong.”

Either way, I would have changed the headline, along the lines of McBride’s suggestions, to temper that “Ever.”

Finally, as Don Wolfensberger, congressional scholar at the Woodrow Wilson International Center for Scholars in Washington, pointed out, there was a slight mistake in the story. When Cillizza was referring to the previous third-year high for polarization he wrote this: “The previous high was George W. Bush in 2007, when he had a 59 percent difference in job approval ratings.”

That year, 2007, was Bush’s seventh in office, not his third. In 2007, Bush’s gap was 66 percent. In his third year, 2003, the gap was indeed 59 percent.