That's just absolute nonsense.
For one thing, Trump's negatives are the result of relentless and ongoing efforts.
Hillary's negatives are despite a persistent effort to prop her up; they are more persistent, and she is much less likely to be able to rehabilitate them.
Given the profound, even breathtaking enthusiasm gap, Trump easily has a chance to wipe Hillary out in the general election.
Hypothetical voter matchups 8 months out are the epitome of propaganda; at this point in 1980, Reagan was about 30 points behind an incumbent, and he still blew him out.
Furthermore, Donald Trump can help redefine the GOP demographic map, with the result doing so much damage to the Democrat party, that they will be relegated to minority status at the federal level for decades to come...