Bill Kristol said this on FoxNews Sunday:

So there are a lot of these voters [30 and under]. They are by definition less committed, I think, they’ve only voted once or twice [bold mine-DL]. Obama took them 2 to 1 in 2008. This is where the Ryan pick can make a bigger difference than people understand. The Romney-Ryan ticket is now younger than the Obama-Biden ticket.

When Paul Ryan, the clip we showed at the beginning of the first panel says this is a defining moment, this is our generation’s time, suddenly you could feel if you’re 27 years old that, gee, you know, the Republican Party is speaking for me and for the future whereas in 2008, of course, it was entirely the other way with Obama running against McCain.

So I really think among young voters, there are more swing voters among young voters. And I think Ryan can make a big difference among them.

I don’t know why this idea is catching on, but I suspect that it has something to do with the desire on the part of some pundits and journalists to have a Republican equivalent to Obama. There is a desire to identify and promote a young, charismatic Republican for this role, and there is a related assumption that this sort of Republican will be more appealing to younger voters by dint of his youth and charisma. Many pundits and journalists wanted to put Rubio in this role as “the Republican Obama,” and he may still have his chance, but for now Ryan will have to do. Much like the Romney-Ryan “movement” that is now mobilizing around the country, Ryan’s appeal to young voters is one of those ideas that has no real supporting evidence.

Millennial voters have been voting disproportionately for Democratic candidates for the last three cycles. Even in 2004 and 2010, Millennials favored Democrats by 14 points above average. Voting patterns of previous generations suggest that political leanings established at a young age persist over time. As the linked Pew report put it:

The clearest pattern is that younger voters who turned 18 during the presidencies of Clinton, Bush or Obama –the younger members of Gen X and the Millennial generation – have typically voted much more Democratic than the average.

It’s simply not the case that there are “more swing voters among young voters.” Millennials have supported Democrats by a wide margin in every election since 2004. The same holds true for most voters that turned 18 in the Clinton years, except for the 2004 election. Whatever theoretical appeal Ryan and his plan ought to have for young voters, there is no evidence that he and his plan have such an appeal in reality.

Update: According to Rasmussen, likely voters aged 18-39 believe Biden is more qualified than Ryan to be President. Biden leads Ryan among these voters by 12 points on this question. 24% are unsure. They are the only age group to side with Biden. Older voters tend to favor Ryan, and those 65+ give him a 22-point lead on this question. This is the reverse of what most people assume should happen.