You are engaging in the logical fallacy of the slippery slope: "If A, then B, then C," without showing the causal chain.
If Lott is so damaged by this mess (or is so spineless, or so self-centered and egotistical) that he must resign from the Senate in addition to his post as Majority Leader, then he will be completely useless as Majority Leader anyway, and the Republican agenda goes nowhere, and we get the 2004 campaign of Trent Lott's stupid remark being played over footage from Birmingham, Little Rock, and Selma.