Mike, no you cannot split your vote 50-50. You have to vote the same for all securities of the same type for each account.
If you own dimes in more than one brokerage acct, as I do, you can vote each acct differently. But if you own all in one acct, you have to make a choice.
By the way, if you also own preferreds or commons in the same acct, you CAN vote those securities differently as you have a different ballot for each security, from each broker.