It's hard to predict who's going to have more fun running against party-switching Long Island congressman Michael Forbes next year -- his Republican opponent in the general election or whatever Democratic rival he ends up attracting in the primaries. Both sides will find a tantalizing paper trail to use against Forbes.

The former Republican was trotted out to share the spotlight with President Clinton at a Democratic press conference on Capitol Hill last week. Forbes was the only rank-and-file House Democrat who got to speak, and he was introduced affectionately by the president he once voted to impeach: "I have letters in my files," said Bill Clinton, "that Mike Forbes wrote me when he was a member of the Republican Caucus about the importance of our education agenda to the children that he represented."

One can understand the political impulse at work here, but it was probably a mistake for the president to suggest looking through the files for old Mike Forbes letters. THE SCRAPBOOK, it so happens, found quite a few in its own files, and they make for poignant reading.

There's Forbes's 1997 fund-raising letter for mentor Al D'Amato, for example: "Whoever emerges as Al's Democratic opponent, Geraldine Ferraro, Chuck Schumer, or Mark Green, their liberal spending will take us back to the Bad Old Days." Not to mention this "Very Urgent Message" to constituents earlier this very year: "The Democrats have shown their cards. They are going to throw everything they have at me in the next election because they want revenge. They want to punish me for voting my conscience on the Articles of Impeachment. If you could stand with me and give $ 100, $ 75, $ 50 or even $ 35 or $ 20 -- even if you could only give $ 10 it will help me show that in New York we stick by our own."

Yes, they stick by their own.