(CNN) With Vermont Sen. Bernie Sanders' decision to end his campaign on Wednesday, it's now official: Former Vice President Joe Biden will be the Democratic presidential nominee this fall.

And Biden starts the general election against President Donald Trump as the front-runner -- albeit not a huge one.

Start with polling. A new Quinnipiac University national poll released Wednesday afternoon put Biden at 49% to Trump's 41%.

That's broadly consistent with the Real Clear Politics average of all general election matchups between the two; RCP shows Biden with an average of a 6-point lead over Sanders.

But the presidential election isn't a national popular vote, you will say. And remember what happened in 2016, you will note.

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