This may be a promising seat for a centrist Republican or a Latino of either party to run for. This district may not be definite, but it would be nice to see finalized. This is based on pending handouts for review.
It has the cities of Rancho Cucamonga, Ontario, Chino Hills, Chino, Montclair and Pomona.
Let us look at the partisan demographics
This is from the odd year registration report from February 2011
One thing is we need to look at the partisan statistics.
42% Democratic Party, 35% Republican Party and 18% Decline to State. It would be a district that would be very competitive and would not want an extreme ideologue from either party.