Unless you negotiate with your DM, and play a variant Druid who gets undead turning instead of, say, wildshaping. ^_^
Then again, Druids can only be LN, NG, CN, NE, or TN. Paladins must be LG (and CG, CE, or LE if you use the variant paladins in UA). Which means, without changing alignments and losing some of your Druid-ness, no druid can become a paladin, regardless.
Then again, Druids can only be LN, NG, CN, NE, or TN. Paladins must be LG (and CG, CE, or LE if you use the variant paladins in UA). Which means, without changing alignments and losing some of your Druid-ness, no druid can become a paladin, regardless.