1) every item in the Contract with America except term limits passed the house.
2) every item in the Contract except the two constitutional amendments became law within two years in some form.
3) the "embarassing" political losses of which you speak only occured in the Nov. 98 election -- and he had a lot of help in bringing those about... there is plenty of blame to go around on that one.
4) the drift of which you speak only came about, IMHO, after Gingrich was gone and Tom DeLay decided to spend his way into a permanent majority.
-- I could go on, but that's enough for a start
The embarrassing political losses of which I speak are things like Gingrich's disastrous "Government Shutdown of '95" (which also had the incidental effect of getting Monica and Slick together); getting his ass kicked on Medicare reform; getting rolled several times in making budget deals; and generally making himself the issue for the 1996 election; and so on. Clinton was on the ropes after the '94 elections; Newt handed everything back to him, and more.
Gingrich was a disaster as Speaker.