If Gore is elected in 2000 and re-elected in 2004, you'll have 16 consecutive years of a Democratic White House, mostly with a Democratic Congress to boot. That means the Republican Party will be doing a
lot of soul-searching from 2004 onwards, just as the Democratic Party did with the DLC in '84.
The question is: who can become TTL's Republican Party equivalent of Bill Clinton; a Third Way Republican to declare "the era of small-government conservatism is over!"
John McCain is an obvious choice, given his chameleonic political nature, but he may be insufficiently moderate in this world. Arlen Specter will have the bona fides, but he's also severely lacking in the charisma department. Maybe Christie Todd Whitman?
Best case scenario: Gore (inexplicably) keeps Lieberman on the ticket in 2004, and as the nominee, Lieberman loses to the New Republican ticket of Whitman/Specter:
Joseph I. Lieberman/Russell D. Feingold (Democratic) -- 246 EV
Christine Todd Whitman/Arlen J. Specter (Republican) -- 292 EV