What year did it become impossible for a POTUS candidate to get a 50-state sweep?

[Plankton5165]

In 1984, Reagan won 49 states out of 50. He almost won Walter Mondale's home state Minnesota, which Mondale carried by just 18 pips (0.18% of the vote).

In 1988, Bush did worse than Reagan, but still better than anyone since then. (426 to 111)

Clinton did worse, but got 370 in 1992, and 379 in 1996. He also won a lot of states by bigger margins than in 1992.

2000, though, was extremely close, and that is, in a way, probably an understatement. Bush won 271 to 266, and Gore won the popular vote.

2004, though, was also close, 286 to 251, and I'm not even sure if Kerry was as worthy as almost winning as like Nixon in 1960 or Ford in 1976.

2008, Obama beat McCain 365 to 173. Slightly smaller than both of Clinton's wins, but you people claim that this was Obama's "ceiling".

So I ask this, what year did it become impossible for a presidential candidate to get a 50-state sweep? I only included options from 1988 to 2004.