The question of whether a politician needs to vote the will of his constituents is open- ended. I guess it depends on the issue, the trust level between the voters and their representatives and how much blind obedience is expected by the constituents,
It is very much apparent, that in a Texas local election the two words " raise taxes" is a sure way to lose. In the New York City mayoral race,raising taxes is part of the conversation, the question being on whom and how much.
I remember the day TARP was being voted on where the Congressional offices switchboards were overloaded with callers demanding that the legislators vote no. Locally, the commenters on our forum were adamantly against it but I was not because I had read that our country was going into a tailspin and there wasn't another viable option. Congress voted TARP down and Wall Street immediately stared crashing. A few days later, Congress passed TARP and it turned out to be a wise decision. It was not a formula for future legislation. It was a once in a life time gamble that worked. In this case the voters were wrong but many of the politicians who went against their wishes are no longer in office.
After Sandy Hook ,the nation overwhelmingly wanted Congress to pass a mandatory background check but the Senate failed to pick up the 60 votes to send the legislature to the House where it was not going to pass or even put up for a vote. There wasn't any consequences for the politicians who voted against the will of their constituents.
I don't want to micromanage my representatives ,although I disagree with them on a daily basis. I disagreed with their philosophy when they were elected,so I don't expect them to change ,just to suit the minority;" to the victor goes the spoils." Yes,there is that old adage " they work for us" but that's only a tool if you live in a competitive district.
If you have watched any news at all,you have seen politicians being questioned on how they will vote on a military strike on Syria. Everyone of those politicians are receiving calls,10-1,against any type of intervention. Those legislators have been given a secret briefing to look at the intelligence but they cannot tell their voters what they know. It is at that time where a politician has to vote their conscience on what they know and put country ahead of politics. There might not be a reason for a military solution but either way ,they are the ones who have to live with the ramification of their one vote.