This is one of those Sundays where the guests were booked days ago to discuss Topic A and, due to late-breaking news, will now be forced to address an unpleasant Topic B as well. Topic A this morning is tax reform, with various Republican heavy-hitters scheduled to defend the House bill and give their prognosis for passage in the Senate. Treasury secretary Steve Mnuchin will be on “Face the Nation” and “State of the Union” while House Ways and Means chairman Kevin Brady is the lead guest on “Fox News Sunday.” White House legislative director Marc Short is also on tap for “Meet the Press.” Question one: How many middle-class Americans will see a tax hike under GOP proposals? Mitch McConnell used to say none would. Now he’s stepped back from that. Hmmmm.

Topic B, of course, is the kerfuffle over Roy Moore allegedly having dated teenagers while in his 30s. Mnuchin, Brady, and Short will all be pressed on whether they think he should drop out as will Moore’s would-be colleagues in the Senate — Pat Toomey will be on “Meet the Press” while Tim Scott sits down with “Face the Nation.” They may also be asked whether the Senate should seat Moore if he wins the election or expel him. Their response will say a lot about where the Republican caucus stands right now.

There’s a Topic C this morning too although it feels like it happened years ago now. That’d be the wipeout in Virginia on Tuesday night. DNC chair Tom Perez will take his victory lap on “This Week,” where he’ll be followed by centrist Republican grump John Kasich. Kasich will also be on “State of the Union” to lament the state of the party and do his other usual shtick. If any GOPer is likely to go off on Moore with both barrels, it’s him. What does he have to lose? The full line-up is at the AP.