I don't know why you think you have to force me to agree with you. I don't. Period.
I neither can or will "force" you to do anything.
I will, however, attempt to make you see that even though you do not agree with a politician who is elected head of state, he or she still represents you, because he or she represents EVERY. SINGLE. CITIZEN of the country he/she is elected to head.
In a representative democracy, the people is represented by politicians, the "highest" of which is the President/Prime Minister, who represents the entire nation.
I honestly cannot see what the problem is here.
Let's take the claim: "Bush wasn't my president! He didn't represent me!" and deconstruct it.
Now, we know one relevant fact here: George Walker Bush was elected POTUS. That means that he WAS President of the US.
Now, as for your statements "He wasn't my president", and "he didn't represent me":
Since we have established that Bush was POTUS, and this cannot be changed, we now need to put your statements into this context.
Someone who isn't American can easily say: "Bush isn't my president", because, sure enough, Bush wasn't Prime Minister of Canada, or President of Mexico, etc. An inhabitant of either of those two countries would not be under American authority, and therefore not be represented by Bush.
However!
An American cannot say: "Bush isn't my president!", because in saying so, he or she is saying one of two things, both obviously false:
1: Bush is not POTUS (which he indeed is/was)
or
2: I am not American. (which the speaker indeed is/was. This, however, can change, if the speaker gives up US citizenship. In that case, the statement becomes true)
Since both claims are erroneous, the only conclusion left, is that Bush WAS, indeed, the representative of every single US citizen.