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How realistic are Najib and MCA when they boast of capturing Penang in GE 15?
Nothing is impossible but it is highly unlikely that they will gain enough Chinese votes.
The last time the MCA won any seat in Penang was in 2004 at GE 11. It had 4 seats. After that, it lost. In GE 12, GE 13 and GE 14, it won nothing.

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GE 14: 2018
PH 37 seats versus BN 3 seats
https://en.m.wikipedia.org/wiki/2018_Penang_state_election
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GE 13: 2013
PR 30 seats versus BN 10 seats
https://en.m.wikipedia.org/wiki/2013_Penang_state_election
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GE 12: 2013
PR 29 seats versus BN 11 seats
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