Some because they think all elected officials are slimy crooks.
Some because they do truly believe that all Clinton's 'illegalities' were related to his personal life.
Some because the Gennifer Flowers/Paula Jones/Whitewater stuff happened beore he was President. (The logic is 'if the people in Arkansas didn't mind, why should I?).
Some because they buy into the Democratic spin that 'most people would lie under oath about an infidelity to protect a child' (even one in college).
Some because they think there is something basically unfair about 'overturning an election' based on personal foibles.
Many people who know all the details about Vince Foster are waiting for the 'smoking gun' as evidence of wrongdoing. Furthermore, the Foster family has not made an issue of the Clinton involvement, leading to the 'if THEY don't care why should I?' rationale?
Filegate? Louis Freeh was head of the FBI. If he thought (or could prove) the Clinton's did anything wrong, he should have said so. This also comes under the 'all politicians would do this if they had a chance'.
Selling the WH bedroom? The Democrats are the party of the working man (and woman), and they need all the money they can get to keep up with contributions from 'rich corporate Republicans'.
Travelgate? That was Hillary. It was also at the very beginning of his term, and thus they were still in 'learning' mode.
The balance of Clinton's support is a result of the cross-party-lines female vote based on abortion rights, the desire to support Hillary because she's a feminist and being picked on because she's 'strong', and the overwhelming support of minorities.
Last, the economy. Individual self-interest allowed many who would otherwise despise Clinton to literally 'take the money and run'. This allowed people to put aside their queasy feelings while watching the market soar and the 401k grow and grow.
Conservatives cannot be lulled into saying 'if only they knew'. They DO know. Maybe not in all the detail that dedicated Freepers and others know, but they know, all the same.