Surprising lack of One-Term Presidents?

With the back and forth divisions of politics in America the last 10-12 years, you would expect that our presidencies would be back and forth as well.

After all, Congress has gone from Republicans in charge to Democrats in charge to Republicans in charge again in just four years, but we continue to have Presidents re-elected at an amazing rate.

By all indications, George W. Bush, the 43rd President of the United States and Former Texas Governor, should have lost re-election. The economy had taken a 1-2-3 hit.

First were the Enron and Corporate scandals that took their toll on moral on Wall Street around the year 2000/2001.

 "You're not really my dad, are you?"

"No, I'm not. I work on Wall Street, you know, with the big buildings."

- The Family Man, 2000

The second punch came with the dot com bubble bursting right around the same time, as the unstoppable force known as the World Wide Web busted like a Dolly Parton blouse.

WELCOME! YOU'VE GOT MAIL.

Third and most significant were the horrendous attacks of September 11, 2001 during which Wall Street was shutdown for days and stocks fell. Cantor Fitzgerald, a global financial services firm lost 658 employees alone on that fateful day.

WTC Tower 1 burns - September 11, 2001

Of course, Bush received record high popularity between 2001 and 2004, making his re-election nearly inevitable. But for all intents and purposes, given the decline of the economy and a hard war in Iraq by the Summer of 2004, history shows he should have lost re-election.

Assuming that, then John Kerry would have become America's 44th President. President Kerry would have had to deal with the horrific aftermath of Hurricane Katrina In August and September 2005, and then the also-inevitable housing market collapse and economic downturn, leading to the election of a Republican President. Perhaps John McCain, perhaps George Allen (assume he wins in 2006 in a good Republican climate under an unpopular Kerry Presidency), perhaps even Mitt Romney.

Then that President (McCain/Allen/Romney, ect) would have just lost re-election in November 2012 to a Democratic candidate. Maybe something like this:::

Bill Clinton (1993-2001)
George Bush (2001-2005)
John Kerry (2005-2009)
McCain/Allen/Romney (2009-2013)
Obama/Hillary/Whoever (2013-)

My question is, why is it easier to sweep an entire congress out twice within four years, but nearly impossible to beat a President once in four years?

The last one term President, George H.W. Bush (1989-1993)

One thing of note...if only men voted...the results of the last 30 years of Presidential elections wouldn't be too different, except Bill Clinton and Barack Obama would have lost re-election. Is it possible that women voters and certain voting blocs make it next to impossible?