The caption on a picture of incoming U.S. senators in this newspaper's front news section yesterday read "Welcome, Freshmen." But for those of us who live in the nation's capital, the caption might well have read "All in the Families."

The photo showed outgoing Senate Majority Leader Howard H. Baker Jr. (R-Tenn.) greeting senators-elect Albert Gore Jr. (D-Tenn.), John D. Rockefeller IV (D-W.Va.) and Paul Simon (D-Ill).

Ignore Simon for the moment, but only for the moment. We'll get back to him.

Among the three others -- Baker, Gore and Rockefeller -- they and close relatives can count no fewer than 10 members of Congress.

Baker, who has served in the Senate since 1967, followed both his father, Rep. Howard H. Baker Sr. (R-Tenn., 1951-64), and his stepmother, Rep. Irene B. Baker (1964-65), as a member of Congress. His father-in-law was Sen. Everett McKinley Dirksen (R-Ill.), a Senate minority leader.

Gore was elected to the House in 1976, following in the footsteps of his father, Albert Gore Sr., who served in the House from 1939-53 (with a brief interruption for Army service in World War II) and in the Senate from 1953-71. The new senator-elect grew up in Washington when his dad was in Congress, and is a graduate of St. Alban's School here.

Rockefeller's family situation is a bit more complex. A great-grandfather who served in Congress was Nelson W. Aldrich (R-R.I., representative 1879-81, senator 1881-1911). Nelson Aldrich's grandson and senator-elect Rockefeller's uncle, Nelson Aldrich Rockefeller, was vice president and presiding officer of the Senate from 1974 to 1977.

We haven't forgotten senator-elect Simon. He defeated Sen. Charles Percy (R-Ill.), who is senator-elect Rockfeller's father-in-law.

As we said at the outset, All in the Families.