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I'm trying to increase the level of tax on cities. Currently no-one is voting for it except me (3/11 votes). I've looked through this site, and found comments to the effect of 'Your vassals don't like you enough! Get more popular with them!'
That hasn't worked for me. Currently I have three vassals. One has an opinion of me of +87. The other two both have an opinion of me of +100. None of them are voting in favor of this law change (see the screenshot attached). What can I do to get it passed, if +100 opinion is not enough?