Portland’s referendum to protect scenic views could have citywide implications, but the donations flowing into the “Yes” and “No” campaigns in the final days before Tuesday’s election are coming from those with vested real estate interests around the eastern waterfront. Since Oct. 20, developer CPB2 has contributed an additional $20,000 to a political action group trying to defeat Question 2, which could significantly limit the company’s planned redevelopment of 10 acres of land it owns along upper Fore Street.