Well, generally if someone is seen as an opportunist, that would be a bad thing, in any walk of life.
I will try to sincerely answer why this matters to me, but it's not a one liner answer.
First, people want someone that they know where he stands and what he'll do as much as they possibly can. That's rather the point of electing someone isn't it? That's the point of a democracy, making informed decisions, or I thought it was. If someone is consistantly changing depending on what is 'politically expedient' you have no idea what (s)he's going to do. This week (s)he may be taking a stand you approve of, next week it may be something totally different because the wind in some back room changed. That is not a leader. And you are right, the jobs are different, and people in the senater are definitely not leaders. Which is perhaps why we tend to vote for governers more than congressional people when it comes to the presidency. We need people that know how to be a leader. Congress has 2 houses and hundreds of people to balance everything out.
Second, most people know you can't govern by the mood of the week. They want someone who is going to stand up and do what has to be done no matter how hard it is or how much criticism they take for it. Some of what are now considered the most important and pivotal decisions in history were not necessarily popular at the time. And considering how the mood changes from week to week, you just can't run things that way. It's one of the problems with many of our companies these days, they are just thrashing around instead of having long term plans they stick to. It's not that things fundamentally change, it's just someone is having a bad week, or the stock goes down because of something totally unrelated (ups and downs are part of life) and a bunch of people start freaking out. It's often considered that is the difference between a statesman and a politician. A statesman is trying to do what's right, not what's advantageous to his career. That doesn't mean the will of the people should be ignored, but every little whim can't be catered to. Seeing the 'will of the people' and believing it makes sense is different than just trying to get or keep your next job. It has to do with trust.
Do you have the slightest clue where Kerry stands on Iraq, cause I don't. And I don't say that in the interest of partisanship, I say that sincerely. And the topic matters to me. According to the polls it matters to most people.
And of course what Kerry did in the Senate matters. It shows if he can be trusted. Does he take his job and responsiblities seriously, or is it a joy ride, ego thing where he's doing his constituents a big favor? Can he be relied on to pursue the stands he took to get elected? No one wants to elect someone that was lying to them just to get elected. I know lots of Republicans, for example, that elected Bush Sr because he had always been a pro-choice moderate, but upon becoming President he turned into a flaming anti-choice person who did the most damage in that arena of anyone to date. You don't see a problem of thinking you are getting A, but ending up with B?
And then there is Kerry's often cited "it's none of your business" replies. You don't see a problem with an elected official having that kind of response?
The problem with Kerry isn't that he changed his mind, it's that he keeps changing it. And then he tries to marry his various positions together to make it seem that he didn't change his mind, that they are all aspects of the same position, when we all know they are not. It would be different if he said I believed A back whenever, but I now believe I was wrong and believe C. But nooooo, instead he says he beleived A, then B, then D, and now C, but they all are really the same and he didn't change his mind at any time.
He isn't changing because of changing circumstances, he's changing based on what someone told him it'll get him that week.
That is insincerity and hypocracy. People vote on issues, or most do, not the party line. If you don't feel you can trust the person you voted to be mostly truthfull about where they stand and what they'll do, why would you vote for them? I say mostly because we all recognize that this is politics. But even in politics there are limits.
I personally don't believe that Bush is being stubborn. Is he perfect, no, but name me a president that has been. But you know exactly where he stands, and he does what he says. Most people find that refreshing. And Bush has gotten credit for having the most 'transparent' presidency ever, which I think is a good thing. Even my friends on the left give Bush way more credit for integrity than Kerry. They can't stand Kerry and seem to be willing to vote for him only because of the 'party', and I believe that is unfortunate, but then I'm an independent. I could give a crap about either party when all is said and done.
What amazes me most, the very people who seem to like to denigrate politicians the most, who say they are tired of 'politics as usual', are the very people who seem to freak out when they get someone who doesn't play the game.
So it comes down to which politician do you believe you can actually figure out what they are going to do, and do you approve of what that is. Of course if you have a politician that you don't like what they are going to do , and another you have no clue what they are going to do, you are in something of a quandry. If you have one you mostly like what you think they are going to do, then you vote for him. But I've never understood the position "it couldn't be worse" because that's not true, it could be a lot worse.
I mostly approve of what Bush will do. The areas I don't approve, I actually don't think he'll do much, abortion and gay rights. But then from everything I've seen in action (as opposed to words), Kerry's position on those topics is no different. As far as national security, some days he seems to agree with Bush, others he suddenly doesn't. I actually think he'll end up doing what Bush has done, but in a more wishy washy, flim flammy, flip floppy fashion, thus being less effective and causing us grief for decades to come. I think the reality is that Kerry agrees with Bush and is only taking an opposing stand because he believes it'll get him elected. That is dishonest. And as said, while I mostly agree with that stance, I don't think Kerry has the backbone to see it through and will make a far more damaging mess.
On the domestic front, one thing about Kerry and the dems really bothers me. They keep acting like this has been a normal 4 years and the economy is totally 100% Bush's fault. I'll make some allowances for politics and trying to paint the other guy in the worst possible light. But that just isn't so. We were in a recession before Bush took office. They had been warning since 1998 that we were in a lot of trouble. In many ways the end of the 90s were a lot like the 20s, and now is a lot like the 30s except we are better off. The stock market was way over inflated. The government invested a lot of money into it in 1999 to avert it possibly crashing due to Y2K fears, and then pulled that money out in 2000, probably too quickly. And then there was this little event called 9/11. It's a minor miracle that we are doing as well as we are.
And my concern is that the dems are either unwilling to discuss the real issues with the economy, or they really don't know and are completely out of touch. Either way, there can be no real solutions put forth if there is no reality about the situation and what caused it. So I don't see them as having any plausible solutions what so ever, and all their rhetoric and quick fixes are likely to only get us into more trouble.
Going so overboard to denigrate the other guy, being unwilling to discuss the realities, gives me absolutely no confidence in anything the Democrats say.