Lots and lots of Paul Ryan today, plus some other stuff, keeping in mind that we’ll soon be returning to the regular presidential contest, and most likely we’ll find that little changed. Here goes:

1. I’ll start with Brad DeLong on Ryan: It’s the arithmetic. Don’t take a politician seriously until he or she gets that part right.

2. How Ryan brings Mitt Romney’s taxes to zero. Part of Ryan in six charts, from Tim Murphy.

3. Ryan is a flat-out partisan, not a deal-maker. Jonathan Chait has the goods on this one.

4. James Fallows talks to political scientist Sam Popkin about the Ryan selection; Popkin leans to the “co-opting Ryan” side of the question.

5. So does Josh Barro, who points out that it would be useful to a President Romney to have Paul Ryan on board if he wants to defy House conservatives.

For the record: I don’t think we have enough evidence yet to know whether the Ryan pick is Romney’s clever plan to neutralize conservatives — or evidence that Tea Partyers and other extreme conservatives will control a Romney administration. What we have so far seems consistent with both of those theories.

6. What Barack Obama and Paul Ryan — and Mitt Romney — would actually do with Medicare, from Ezra Klein.

7. An interested interview: Derek Thompson checks with the AEI about whether liberals are being unfair about Ryan.

8. Mitt Romney can’t win if Ryan costs him votes from seniors, Nate Cohn argues.

9. Does Paul Ryan “heart” unemployment? Well, Timothy Noah’s language is probably a bit over the top (he’s putting words in other people’s mouths), but he’s right that Ryan has claimed principled reasons for doing nothing about unemployment.

10. As far as politics go, if House Republicans are bracing and preparing for attacks, doesn’t that suggest that maybe Ryan isn’t a political plus? Alex Isenstadt reports.

11. The next Romney attack ad on welfare. Steve Benen seems to remember a candidate who just last week said that candidates should pull ads that fact checkers call false, not double up on them. Must be some other Mitt Romney.

12. See also Alec MacGillis on Romney’s questionable claims to the high ground.

13. Getting away from the campaign a little: You’re going to want to read the first in a series of posts by Martin Gilens over at the Monkey Cage; he’s blogging about his new book on economic inequality and political power.

14. And you know who is raising moneyon the Ryan selection? That would be Rob Zerban, Ryan’s opponent for the House of Representatives.