More good news for John McCain.

According to a new NBC-Wall Street Journal poll, the Arizonan is “facing unexpectedly formidable challenges” and trails Rudy Giuliani in a head-to-head match-up by 20 points nationally.

The Journal concludes what we’ve seen evolving for some time, that “2008 is shaping up as the worst election year in three decades to be the candidate of the Republican establishment, the spot some in the party think Mr. McCain has assumed.”

Which is why, as we talked about earlier this week, Republicans may buck the trend of choosing the candidate of inevitability this time around.

Given the state of his popularity nowadays, it’s downright shocking to believe that not so long ago, John McCain was a maverick, someone who commanded so much respect from both parties that John Kerry allegedly offered him the vice presidency on the Democratic ticket.

The great irony is that the 2003-2004 version of John McCain would be a lock for 2008. But since he spent the years in between becoming more and more submissive to George W. Bush (regarding the Iraq war in particular), cozying up to the Christian right and, by all accounts, diluting himself to jell with the Republican base, he’s left himself in a compromising position now that public opinion has turned against the GOP en masse.

As a result, the missed opportunity to form a Kerry-McCain juggernaut in 2004 may be the closest McCain ever got to the presidency. Then again, there’s still ample opportunity for Giuliani to falter.