There's so much to say about this, but like any good square, I'm going to try it in four points.
1. Some will call this confident; others will call it a bit desperate.
The "confident" crowd will point out that Romney has just done what no one thought he'd do -- embrace controversy for the sake of principle and throw his lot in decidedly and emphatically with conservatives during a general election.
This wasn't supposed to happen, was it? Romney was only "severely conservative" in the primary. He was the political equivalent of a giant, fluffy, marshmallow of an airbag. He was so sold on political safety that he didn't realize how dangerous it would be to "play it safe", and it wouldn't dawn on him until November 7.
Well, maybe not, this pick says. Maybe he's severely committed to entitlement reform and the kind of big ideas that everyone thought he'd avoid. Maybe he's willing to take political risks -- both in electoral politics and governing.
After all, conservatives were doing the despondent thing big-time the last few weeks, worried that even if Romney won, he'd always be thinking about the next win and gearing his agenda toward it.
That's the group that will call the Ryan pick "confident."
But the other camp will say that it's a sign of desperation -- that Romney was carefully watching polls showing Obama inching ahead in battleground after battleground, and a switch flipped in Mitt, and he panicked.
But that's wrong on a number of levels.
First, Romney isn't the kind of guy to panic. He's far more likely to be strategically intransigent; in fact, we've seen that over and over since the presidential primary began. So it's unreasonable to think that he saw some battleground polls that were STILL within the margin of error and freaked out about it.
A challenger does not freak out about margin of error polling. A challenger does not freak out when the incumbent has 45% or 46% approval rating. Even more, a challenger whose name is the Romney operation doesn't freak out about it.
Second, if this really were some variant of desperation, why didn't anyone call it that during Veepstakes? Sure, tons of people (including me) said Ryan was an enormous risk, but very few put the potential pick in the context of Romney being desperate.
Just watch -- Romney's opponents will unload the desperate charge over and over again in the coming days, but if it's true, then someone would have sneaked in at night and replaced Romney's soul with that of a panicked chicken who sees Foster Farms behind every external stimulus.
2. Romney has just threatened his entire candidacy.
Over the past months, we've been seeing a fascinating dynamic at work that no one's really talking about.
Barack Obama is doing much better with seniors this time than he did in 2008. Meanwhile, he's doing much worse with 35-54 year-olds.
In most head-to-head matchups, Romney leads the 35-54 year old set, while Obama is either tied or ahead with the golden set.
That's a MUCH better position for Romney than Obama, because seniors voted for McCain by 7% over Obama, and are, therefore, much more inclined to swing Romney's way than 35-54 year olds are to swing Obama's.
Well, because the 35-54 year old set has clearly had enough of Obama, and it's going to take quite a bit for the president to make them believe again. But seniors, in theory, should be easier for Romney to capture.
That means Obama has to tie or outright win seniors to compensate for losing the 35-54 year old set (he's been consistently leading the 55 year old-64 year old group, btw).
In short, both candidates need seniors to win. It's the tiebreaker in this election, and they were very recently voting Republican.
That's why the Ryan pick is so potentially damaging. It could alienate the group that appears most politically pliable, and that's the group that's most susceptible to demagoguery on Medicare, and in case you hadn't noticed, that's sort of Paul Ryan's lot in life. No one really grows up telling their parents they want to either be a firefighter or demagogued on Medicare, but sometimes those are the cards.
The Ryan pick won't alienate the 35-54 year old set or the youngins'. In fact, both groups will probably respect and be fairly pleased with the pick and the ideas Ryan talks about. But that's not the point. Seniors are the point of this election.
3. Ryan could save Romney's candidacy.
For months, conservatives have begged Mitt to get specific, urged him to absorb the fact that he probably can't win unless he offers a compelling, big vision.
Well, this pick signals that he's committed to doing both of those things.
Whether or not voters ultimately agree with a candidate on particular positions, they nearly always respect principle, conviction, and big ideas. Paul Ryan brings all those things to the ticket, and has the chance to confer all that on Romney like some Wisconsin version of pixie dust.
And there's this to remember -- Scott Walker, Wisconsin, Upset, Shock, Pseudo-Blowout.
Picking Ryan alone is enough to get conservatives excited, but picking him in the context of Rob Portman and Tim Pawlenty? That's just about as thrilling as getting visited by the Ghost of Ronald Reagan on a Christmas Eve.
This isn't Marco Rubio (who I still think would've been, by far, the strongest choice), but for most conservatives, it's more than good enough.
4. Ryan will be no ordinary runningmate -- both for good and ill.
It's notoriously common to overrate the importance of a Veep on election, but contrary to common wisdom, Sarah Palin didn't do McCain in, and George Bush got over 400 electoral votes with Dan Quayle attached to his name. So presidential winners have survived controversial Veeps and will survive them again.
But Ryan is a much bigger deal, because his budget plan is so integral to the GOP's future -- and now Mitt Romney's.
Democrats will try to make the election a referendum on Ryan's budget plan, while Republicans will try to steer it to a referendum on Obama's first term.
Well, that just got much harder for Republicans, if only for a very cosmetic, trivial reason. Paul Ryan is the only shiny object in this election now.
Think about it. No one's interested in Joe Biden, Obama is the incumbent president, and Romney is on his second presidential run. They're all old news.
But Paul Ryan is the only new guy in the conversation, and as such, will be included (even the subject!) of a much bigger proportion of that chatter than many past vice-presidential runningmates.
Now... having said that, here's the potential upside for Romney -- Ryan is extraordinarily good at what he does and is probably a better messenger than Mitt himself, so if he IS, actually, at the center of more attention than past Veeps, then bully for Mitt!
After all, Sarah Palin was a magnet for the media in 2008, but she wasn't prepared to handle any of it -- least of all questions on national policy. Once everyone realized that, they tore at her even harder.
But Paul Ryan is eminently qualified to handle and even thrive in a context where people are pressing him.
So there -- like any good square, four points, and... this election just got way more interesting and even more fun.