Hugh Sidey, whose personal portraits of America's chief executives appeared in Time magazine's "The Presidency" column over four decades, died Monday. He was 78.

His brother, Ed Sidey, said other relatives told him that Sidey had suffered a heart attack in Paris. He lived in suburban Potomac, Md.

Sidey, who served as Time's White House correspondent and its Washington bureau chief, wrote "The Presidency" from 1966 to 1996. He was a contributing editor to the newsweekly at the time of his death.

Reflecting on the presidents in a 2003 interview, Sidey said: "They are not as tall or articulate as you think they should be. And they're not super people, so that is a bit of a letdown. Then you begin to understand, though, when you write about them as I have, how vital they are to the American system."

Beginning with John F. Kennedy, whom he once interviewed during a swim at the White House, Sidey enjoyed unusual access to the presidents. He tended to focus on the personal dimensions of those in power, and his balanced portraits, whether sympathetic or critical, often endeared him to the men who occupied the Oval Office.

"He proved you can write about people in power and still be the gentleman journalist," said James Carney, Washington bureau chief for the magazine. "He's in some ways the model we all aspire to."

Sidey was on hand for many of the triumphs and tragedies the presidents experienced.

He was in Dallas when Kennedy was assassinated in 1963, traveled extensively with Lyndon B. Johnson, whom he considered the most fascinating person he ever knew, and flew to China with Richard M. Nixon in 1972.

He walked through Moscow's Red Square with Ronald Reagan in 1988 and, last year, was aboard the plane that carried Reagan's body to California.

In a statement, former first lady Nancy Reagan recalled that event and Sidey's presence a few weeks ago at the dedication of the Air Force One Pavilion at the Reagan Library. "Today, I have lost a dear friend and America has lost one of its most trusted journalists," she said.

Sidey was hired by Life magazine in New York in 1955 and went to Washington in 1957 to cover the administration of Dwight D. Eisenhower. He later joined the Washington staff of Time and wrote about every president from Eisenhower to George W. Bush.

He wrote or contributed to seven books on the chief executive, including "Hugh Sidey's Portraits of the Presidents" (2004). He also was a chairman of the White House Historical Association.

Sidey appeared as a panelist on the television program "Agronsky & Company" and its successor, "Inside Washington," for nearly 25 years.

A fourth-generation newsman, Sidey was born in Greenfield, Iowa, on Sept. 3, 1927, and grew up working on his father's weekly newspaper. After serving in the Army, he received a bachelor's degree in journalism from Iowa State College in 1950. He worked for newspapers in Council Bluffs, Iowa, and Omaha, Neb., before joining Time Inc.

Sidey and his wife, Anne, married in 1953 and raised three daughters and a son.