If the economy is strong, Bush could not have won without a mandate for his tax cut. The economy is either fragile or strong. Therefore, Congress should pass Bush's tax cut. A candidate who wins most of the states has a mandate. Since Bush didn't win a plurality of the votes, his surrogates divide the electorate into larger units of which Bush did win a plurality.
All voters reside in states.
Bush won the most states. Therefore, Bush has a mandate. More people intended to vote for Bush than for Gore. Having ridiculed the unfalsifiable Democratic claim that more people in Florida intended to vote for Gore than for Bush, Republicans turn around and claim that more people throughout the country intended to vote for Bush than for Gore. Imagine what happened in California and a lot of other states.