After adamant refusals and in view of the chaos reigning in the GOP House caucus, Paul Ryan is finally considering a run for speaker. Since Justin Amash probably won't get it, here are three reasons why Ryan should:

1. He's the only one who can unite the House factions.

The reason why the House has been in such chaos has been the brewing civil war between the GOP establishment and the Tea Party. The Tea Party faction in the House is big enough to frustrate policymaking, but not big enough to enforce its agenda — even if it had one. The Tea Party thinks the establishment are a bunch of squishy corporate sell-outs, and the establishment thinks the Tea Party are a bunch of crazies who are running the party into the ground. (And both sides have a point.)

Both sides actually need each other. The Tea Party needs the establishment to gets things done (and, perhaps, dish out a dose of reality), and the establishment needs the Tea Party because its corporatist, pseudo-centrist political agenda is a political loser and a policy disaster. The problem is that there is absolutely no one who is trusted by both sides.

No one, that is, except Paul Ryan. Ryan has taken lumps for putting forward entitlement reform plans, which gives him respect on the right, but he's a wonk and occasional dealmaker, which gives him respect with the establishment. He's the only guy who can unite the factions.

2. He doesn't just have political smarts. He has an agenda.

Paul Ryan is a really smart guy. A veteran congressman, he knows how the House and national politics work. That's clearly important.

But something is even more important: an agenda. One reason why the Tea Party caucus in the House has been so ineffective is that they know what they're against, but they don't know what they're for. Putting forward proposals gives you momentum and allows people to unite behind your proposals. It drives the conversation.

Paul Ryan is the perfect person for this. We need a Tea Party Speaker, but one who is actually smart about policy and has a vision for the future. Paul Ryan fits the bill.

3. He can leave a legacy.

Right now, the House GOP caucus is a mess. But Paul Ryan is young, and there is a lot of time ahead. If there is a Republican in the White House in 2016 or beyond, a policy-driven and politically smart speaker can actually have a tremendous impact in shaping the future of America. Any Republican president, or at least any smart one, would have to view Paul Ryan not as a floor leader and enforcer as George W. Bush tended to see his Republican speakers, but rather as a genuine player. And, for that matter, any Democratic president would have to make deals with Ryan. And if he can maintain his reputation as an honest broker with both conservatives and Democrats — a tricky thing to be sure, but he's managed it for longer than most — then he can also have a dramatic impact on policy several years down the line.

Only one modern speaker is remembered for changing America, and that's Newt Gingrich. Most other speakers — Tip O'Neill most famously — are remembered mostly as dealmakers and political inside-men, rather than people who have left a tangible legacy. Paul Ryan could change that, and that's got to be attractive.