When Toby and Gaines exit the Russell Senate office building, it's not the real one, but the Postal Museum near Union Station. The real Russell building is a lot closer to the Capitol, which can be seen far in the distance. The Dubliner restaurant is clearly seen in the close background with the Irish flag flying.
C.J.: That time I accused the Speaker of welshing on committee assignments and had to apologize to the Welsh people... slow news day.
Will: Bob Russell is so dull, his Secret Service code name is "Bob Russell."
Bartlet: Social Security is the third rail of American politics. Touch it, and you die.
Toby: That's 'cause the third rail's where all the power is.
Toby: What if I do it? I'll do all the negotiating, you'll have total deniability, no one else in this building has to know.
Bartlet: And if it blows up, I'm supposed to pretend we've never met?
Toby: We'll always have Paris.
"We'll always have Paris" is one of the most famous lines in the history of the film industry (it was voted 43rd in AFI's "100 Years... 100 Movie Quotes"). It's a line from the 1942 film Casablanca, where Rick tells "we'll always..." to Ilsa, meaning they'll have the memory of the peak of their love.