Final answer:
The percentage of voters who were for the candidate in the last poll was 25%. This is found by subtracting the 40% increase from the current 65% support.
Step-by-step explanation:
If a political candidate hears that 65% of the voters are for him in the polls, up 40% since the last poll, we need to determine what percentage of voters were for the candidate based on the last poll. To find this, we subtract the increase from the current percentage. So, we have 65% - 40%, which equals 25%. Therefore, in the last poll, 25% of voters were in favor of the candidate.