“They’ve been best friends, they pick on each other, love each other, hate each other … it’s just like anybody’s family,” says Calista Flockhart about the stormy/sweet relationship between Kitty, the conservative daughter she plays, and Sally Field’s widowed, liberal-minded mother Nora on the ABC series “Brothers & Sisters.”

Field concurs, adding that what makes this volatile parent/adult child matchup so dramatically rich — in the already fraught matrix of dysfunction and strength that is the Walker clan — is that “Nora needs Kitty as much as Kitty needs Nora. They’re the most similar to each other in the family, so they know how to push each other’s buttons.”

Their biggest dustup this past season has been over the Iraq conflict. Says Flockhart, “Nora was seemingly holding Kitty responsible for sending (Nora’s younger brother) Justin to war. So they have their issues.”

Offscreen, however, it’s all respect and friendship. Flockhart says she loves working with her TV mother, and Field says Flockhart has “zero, zero ego. It’s always about how we can get it better. She’s just sensational.”

For both actresses, taking on the roles created by acclaimed playwright Jon Robin Baitz was a case of excitement at the prospect of breaking primetime barriers in the portrayal of contemporary women.

“There are not a lot of youngish Republican women on TV,” says Flockhart, whose character is currently communications director for (and fiancee of) a GOP senator played by Rob Lowe. “She’s passionate about her political views, but she’s not rigid.”

Meanwhile, Field, who replaced Betty Buckley from the original pilot, says she responded to Baitz’s and executive producer Ken Olin’s description of Nora as a baby boomer in her early 60s.

“We are not the stereotype of the ‘Father Knows Best’ mother who stands around, applauds everybody else and puts salve on their wounds,” says Field, herself a parent and grandparent. “We are to be reckoned with ourselves; we are colorful and an important group who have changed a lot of images of who women are.”

Favorite scene:

Field: “The last scene of the season. The episode is tremendously dramatic and sad, but in the last scene we take it all and do something unexpected and frolicking and irreverent, and it ties the whole season together.”

Flockhart: “I love doing scenes with Matthew (Rhys, as her gay brother). Matthew and I always seem to butt heads on the show.”

Where you’d like to see your character go next season:

Field: “They talk about Nora finding somebody, but really I’ve loved the fact that I haven’t known anything from week to week. ”

Flockhart: “Plot really doesn’t interest me, whether she gets married or has a baby. For me, it’s about her daily life, what’s going on with her emotionally.”

TV guilty pleasure:

Field: “I come home at the weirdest hours, so my utter and total addiction is Turner Classic Movies, because it’s there all the time.”

Flockhart: “We don’t watch a lot of TV.”