Thou shalt not get caught.
Remember reagan's "11th Commandment"? Thou shalt not speak ill of other republi-CONS.
But seriously... TRULY, with many of these people, I can't help but suspect that they're just Macchiavellian enough to think of their party and their monopolies on power FIRST, and propriety, ethics and morals SECOND. Some of 'em are outraged at Foley because they're afraid he's gonna bring their "House" down. Not necessarily because of what he did. The fact that he got caught, and is making them all look bad, and giving them a huge eleventh-hour headache - THAT'S what's most galling to them. He's worthless to them because, in the end, he got caught - he's thereby proven himself to be NOT one of them, so they have no use for him.
You simply HAVE TO reach this conclusion because enough of them knew something nasty was up with him and the pages, AND DID NOTHING ABOUT IT, for months and months. So in the best end-justifies-the-means tradition, they were able to reconcile it as somehow being okay. It was evidently not such a big problem that they couldn't easily sweep it under the rug and forget they'd heard anything about it - until it hit the national news. If they'd REALLY cared about the morality of it, they'd have been on his ass last year.
On edit - just found a NYTimes editorial posted here - that verifies this - Power Trumps EVERYTHING, and the PERPETUATION of that power ranks even HIGHER:
http://www.nytimes.com/2006/10/03/opinion/03tue1.html?_r=2&oref=slogin&oref=slogin(snip)
History suggests that once a political party achieves sweeping power, it will only be a matter of time before the power becomes the entire point. Policy, ideology, ethics all gradually fall away, replaced by a political machine that exists to win elections and dispense the goodies that come as a result. The only surprise in Washington now is that the Congressional Republicans managed to reach that point of decayed purpose so thoroughly, so fast.
That House leaders knew Representative Mark Foley had been sending inappropriate e-mail to Capitol pages and did little about it is terrible. It is also the latest in a long, depressing pattern: When there is a choice between the right thing to do and the easiest route to perpetuation of power, top Republicans always pick wrong.