Given how much is on the line for the Democrats, it’s curious that as John McCain returned from a diplomatic tour of Europe and the Middle East, Barack Obama was on his way home from a tropical vacation. The friendly November playing field that the Democrats anxiously awaited not long ago is tilting more and more towards McCain, whose crossover appeal and “maverick” image are likely the perfect antidote to the star power of the Democratic candidates. New poll numbers show not only show that voters are growing weary of the prolonged Democratic primary, but that they’re crotchety enough to switch sides in November.

• David Paul Kuhn thinks the general-election calculus has been upended: Polling data shows McCain not only wins more independents versus the Democrats in a general-election scenario, but also leads in crossover voters. Forget Obamacans — Republican strategists are dreaming of a return of the Reagan Democrat in the form of the McCain crossover voter. [Politico]

• Vaughn Ververs describes a sense of relief among Republicans due to the divided Democratic party and the opportunity they believe McCain has to expand the electoral map and compete in areas considered solidly blue. [Horserace/CBS News]

• Toby Harnden sees a McCain victory as increasingly likely and lists ten things that could make it happen. Number 5: Clinton becomes the Democratic nominee. Number 6: Obama becomes the Democratic nominee. [Telegraph]

• Likewise, Chuck Todd and Domenico Montanaro see it becoming increasingly harder for Democrats to make up ground in swing states like Colorado, where McCain campaigns today, as the primary race drags on. [First Read/MSNBC]

• Jim Geraghty notes at least one blue state where McCain is still behind: Even with his buddy Joe Lieberman pulling for him, McCain loses Connecticut big to Obama, small to Clinton. [Campaign Spot/National Review]

• Brian C. Mooney posits that record Democratic enthusiasm may be a double-edged sword: Because voters have invested so much in their candidate, they are bound to feel alienated when one loses. Which is why 28 percent of Clinton supporters would vote McCain if she loses, and 19 percent of Obama supporters would vote for McCain if Obama loses. [Boston Globe]

• Craig Crawford looks at those numbers and other indicators of a divided party and concludes that the Democratic candidates may need to run together or hang separately. [CQ Politics]

• Josh Marshall, in a video post, argues that McCain has an Achilles’ Heal — his willingness to continue President Bush’s Iraq strategy. [TPM]

• John Martin notices, however, that McCain used his foreign policy-speech yesterday to “subtly but unmistakably” break from Bush by insisting we work more closely with our allies. [Politico] —Dan Amira

For a complete and regularly updated guide to presidential candidates Hillary Clinton, Barack Obama, and John McCain — from First Love to Most Embarrassing Gaffe — read the 2008 Electopedia.