John Boehner won his second term as Speaker of the House Thursday, re-etching his name into the history books as only the 53rd person to hold that lofty job.

Unfortunately for Boehner, the Speakership is at (or near) its low ebb in terms of raw power thanks to a combination of changing rules in the House and emerging political realities.  

Boehner is charged with overseeing a Republican-controlled House in 2013 that proved close-to ungovernable in 2011 and 2012, riven by broad ideological divides -- both between the parties and within the GOP -- and by a new class of Republicans who viewed compromise as a dirty word.

His first term as Speaker ended with a direct rebuff of his so-called "Plan B" to raise taxes on only those Americans making more than $1 million a year or more and an open revolt among some within his party over his decision not to bring legislation provided funding for victims of Hurricane Sandy to the House floor.

His second term will be dominated by politically perilous negotiations over the debt ceiling as well as an attempt to avoid automatic, across-the-board cuts if Congress can't agree on measures to reduce the debt.  

Boehner faces those monumental challenges with as little power over his House majority as any Speaker in modern memory. There are any number of reasons for that diminution in authority but here the five big ones.

1. Earmarking ban.  One of Boehner's signature pledges when he became Speaker was to get rid of the process by which Members of Congress directed money to their districts or preferred interest groups in spending bills. The sentiment made sense at the time -- there was a huge revolt among Republicans for the over-spending by the federal government -- but it has made Boehner's job much, much harder. Withholding earmarks (or promising them) for Members' pet projects used to be a sure-fire way to rally support behind the preferences of the Speaker. Now, Boehner lacks a hit-close-to-home -- literally -- vehicle to reign in wayward Members.  There is simply no imaginable way that Boehner's "Plan B" would have failed to even make it to the House floor in an age of earmarking.

2. Politics/ideology trumps loyalty. There was a day when relationships trumped all in Congress. The men and women who served together didn't fly back and forth to their home districts all that much -- airline travel was not as ubiquitous as it is today -- and, as a result, they spent lots of time together. That familiarity bred loyalty, allowing the Speaker to draw on deep personal relationships to get his way in touch spots.  Not so much nowadays as personal relationships have largely become a thing of the past in the modern Congress. Now, the key considerations when a Member decides how to vote are some combination of pure ideology and pure politics. Many members who opposed Boehner's "Plan B" liked and respected the Speaker but simply could not take the risk of courting a GOP primary challenge by voting in favor of a tax increase of any sort. Or they refused to break with their principles in support of getting a good but not great compromise with the President.

3. More paths to power.  In the olden days -- like twenty years ago -- the only path to power in the House was getting on the Speaker's good side and slowly but surely climbing the leadership ladder.  If the Speaker liked you, you were golden. If not, better plan on finding a different career some time soon. In the modern media and political world, that's simply not true anymore. As made clear by the likes of Sen. Jim DeMint (S.C.) as well as Reps. Michele Bachmann (Minn.) and Allen West (Fla.), being a renegade who makes your name by bucking the party leadership is a path to power all its own now.  The idea that Bachmann, who has left almost no mark on the House in her three-plus terms there, could, at one point, become a viable presidential candidate would have been unthinkable in past generations of the House. No more. Anyone with an active Twitter feed and an aggressive interest in appearing on cable television can build their own power center, entirely independent of what the Speaker thinks of them.

4. The weakening of political parties.  Just as getting on the wrong side of the Speaker could mean relegation to unpopular committees and no chances to move up in the House ranks, it would also mean that when re-election time came around the purse strings of the party might be closed to you.  Those who cooperated with the Speaker and his or her agenda could be assured that if they happened to find themselves in a tough race the money would be there to save them. But now, the financial world of politics has been turned on its head with the best-funded groups often being outside interests not parties. The Club for Growth, American Crossroads and Americans for Prosperity have all shown the ability -- and willingness -- to spend millions of dollars on their preferred candidates, spending that is almost always in excess of what the party is willing or able to do.  Given that alternative funding mechanism for campaigns, walking in lockstep with the Speaker to get the money he (or she) controls is a thing of the past.

5. Job uncertainty: Being Speaker of the House used to be a job you had until you didn't want to have it anymore.  From 1939 to 1987 -- a span of 48 years -- only 5 men served as Speaker: Sam Rayburn, Joseph Martin, John McCormack, Carl Albert and Tip O'Neill. From 1987 to 2013 -- 26 years -- there have been 6 different Speakers: Jim Wright, Tom Foley, Newt Gingrich, Denny Hastert, Nancy Pelosi and Boehner.  None has stayed in office longer than four terms and each of the previous five Speakers before Boehner were ousted from the job thanks to either a turnover in House control or a personal scandal. (Hat tip to WaPo's Karen Tumulty for making that point first.)  Many rank and file members understand now that if they don't like or get along with the current Speaker, all they need to do is wait a while and the person in the job will likely change.