christopher johnson, susan shirk and john mearsheimer, thank you all three. >> thank you. >> woodruffhill was a historic place to be this week with a papal visit and the surprise resignation of house speaker boehner. of course, those are the main topics for our turn to shields and brooks. that's syndicated columnist mark shields and "new york times" columnist david brooks. welcome, gentlemen. so, mark, surprised about boehner? >> yes. but as lisa reported, too, from the hill, the speaker faced a vote of no confidence. he could have survived but it would have shown him weakened in his own caucus among the republican members. so i think he brought the decision on his own terms. >> woodruff: david, a complete shock for you? >> no, saw it coming months and months and months ago... (laughter) no, obviously since the day he walked in the door, he's had this challenge andeth grown evening more, but i don't think anybody saw it coming in this way. there is a beautiful piece from robert costa in "the washington post" talking about the night before costa was with him on the balcony and boehner