I've stated in the past that news programs of the Trueniverse can appear in Toobworld and not cause a Zonk. So there was no problem having Jenna Maroney, star of 'TGS with Tracy Jordan' (the show within a show on '30 Rock'), appearing on an edition of 'Hardball' with Chris Matthew and Tucker Carlson.
The face time helped boost Matthews' already considerable body of work for the League of Themselves, while Carlson needs just one more fictional appearance as himself to make him eligible for the TV Crossover Hall of Fame.
'Dog Bites Man'
'Tanner On Tanner'
There's also 'The West Wing' and 'Mister Sterling', which both take place in the same alternate Toobworld.