First Mitch Daniels and now this. On Monday, Rep. Paul Ryan (R-Wis.) dashed "the conservative intelligentsia's last best hope to get one of their own in the race" for president. The chairman of the House budget committee announced (again) that he would not seek the GOP presidential nomination. Why is the budget wonk ignoring the pleas of The Weekly Standard, Jeb Bush, and other members of the Republican elite who desperately want him to run? Here, five theories:

1. It's too late
If Ryan had decided to run, he "would have had to start from scratch," and "he did not want to play catch up," says Robert Costa in the National Review. While the Wisconsin conservative does have a political action committee of his own, it's not nearly big enough to compete nationally, and he would have been stuck fielding a campaign team while also juggling a packed schedule of debates and fundraising events — with the first-in-the-nation Iowa caucuses quickly approaching early next year. "It really was late to begin a run from scratch," says Robert Costa in the National Review

2. He didn't really want it
"For Ryan, being president has never been a lifelong ambition," says Stephen F. Hayes at The Weekly Standard. "His consideration of a presidential bid came not because of any desire to be president and, in many respects, came in spite of his inclinations against one." He always wanted to be a wonky Jack Kemp, not a presidential Ronald Reagan.

3. Ryan might be viewed as a one-trick pony
Candidate Ryan "would clearly be an expert on fiscal issues," says Matt Lewis at The Daily Caller. But "what if foreign policy experience suddenly became important? What if Russia invades Georgia?" Ryan "lacks executive experience," and fair or not, he would likely have been perceived as a youthful lightweight on non-fiscal issues.

4. Democrats would have pilloried his Medicare plan
The 41-year-old Wisconsin conservative has "some radical ideas, such as turning Medicare into a voucher system," says Jonathan Capehart at The Washington Post. That plan may play well with conservatives, but turning Ryan's proposal into a campaign issue in the general election had "Democrats swooning over the electoral possibilities." Indeed, says Lewis. The bold plan "would be easily demagogued" by "Mediscare"-trumpeting Democrats.

5. Losing would have damaged his budgetary cause
"One of Ryan’s chief concerns all along was whether an unsuccessful presidential campaign would undermine the GOP's fiscal hawks," says Costa. While he could have recovered from a unsuccessful run, "he worried that his fiscal agenda might end up politically discredited" by "an inglorious end in the snows of New Hampshire or the hills of South Carolina." Perhaps the best role for the fiscally-minded Ryan "is to continue to lead in the House, shaking up the chamber's spending ways and nudging the presidential field in the right direction."