(CNN) The latest CNN/Des Moines Register/Mediacom Iowa poll is undoubtedly good news for former Vice President Joe Biden and Sen. Bernie Sanders as the two lead the large pack of possible contenders for the Democratic nomination for president in 2020.

But the poll also reveals strengths and weaknesses for those two and several other Democratic contenders.

Biden

For Biden, it's mostly a positive picture. The new poll shows him with 81% favorability among likely Democratic caucusgoers. He has the highest support out of 20 possible Democratic candidates -- 27% picked him as their first choice. But there's a big gap between 27% and 81%. Among other candidates, that very good favorability rating (of which Biden's is exceptionally high), could mean a higher number who would support him in the primary. There are a number of reasons this could be, including that Biden hasn't actually declared a run for president yet.

But there's other good news for the former Vice President in the poll -- 64% of the likely Democratic caucusgoers said that Biden has more experience than any other candidate and want him to get in the race. Only three-in-ten said that the time for him as a candidate has passed and he should stay out.

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