Can their ever be another 50 state sweep and how would a person achieve the goal

[Nym90]

If there were some sort of major event just prior to the election that swung things towards (or against) the incumbent. For example, President Bush had a 90 percent approval rating after the 9/11 terror attacks, and thus almost certainly would have won all 50 states if the attacks had happened right before the 2004 election instead of when they did.

Or conversely, President Nixon's approval rating dipped to below 20 percent right before his resignation and thus he almost certainly would have lost all 50 states if the full degree of revelations had come out immediately before the 1972 election as opposed to in 1974.

[Nym90]

If there were some sort of major event just prior to the election that swung things towards (or against) the incumbent. For example, President Bush had a 90 percent approval rating after the 9/11 terror attacks, and thus almost certainly would have won all 50 states if the attacks had happened right before the 2004 election instead of when they did.

Or conversely, President Nixon's approval rating dipped to below 20 percent right before his resignation and thus he almost certainly would have lost all 50 states if the full degree of revelations had come out immediately before the 1972 election as opposed to in 1974.

This. Even so I think Bush would have lost VT and Nixon would have won MS and a handful of rocky mountain states. Have we ever had a 50-state sweep?

Never, though Reagan came very close in 1984, narrowly losing Minnesota. Nixon in 1972 also won 49 states but Massachusetts wasn't particularly close.