What Is A Lie?
Before it is even possible to engage with the question
Is telling lies a part and parcel of politics? Is it impossible to be
in politics without resorting to lies? If YES, why is that?
it is important to distinguish between a causal way of using the term "lie" and the more restrictive sense of that word used in the law and in more careful speech.
In the law, when we talk about a lie (which is called "fraud") we mean a false representation, about a presently existing material fact, made with knowledge of its falsity, with an intent to deceive the person to whom it is communicated.
What Is Not A Lie?
It is easier to talk about that that definition doesn't include.
In the law, making a promise about something you will do in the future, and not living up to that promise is not a lie.
Broken campaign promises are part and parcel of politics and impossible not to resort to.
This is because politicians in democratic systems of government aren't kings. They have to obtain the cooperation of other people to carry out their promises, and sometimes they fail.
Also, circumstances change and new information is discovered over time. So, promises that seemed doable when made and seemed like a good thing to do when made, may prove to be more difficult to accomplish than anticipated, and may turn out to be something that is abandoned because new information reveals a promise to have been, in 20/20 hindsight, a bad idea for an action to take.
The problematic issue, even in a world of honest politicians, is how to not unduly favor politicians who are making promises in good faith that they intend to keep but don't manage to, over politicians who are more careful in making promises and can keep more promises than someone who promised more can. There is a moral hazard for a politician to promise more than they can deliver to get elected, even though the politician knows in advance that some particular promises will be impossible to keep.
More generally, inaccurate predictions about the future are not lies if you believe that they are true when you make them.
In the law, statements made without knowledge of their falsity aren't lies.
Politicians aren't perfect. Indeed, they are particularly vulnerable to misinterpreting facts to fit with their worldviews and political visions. They are also busy people with lots of responsibilities. Sometimes, they assume that a source of credible, even if it is not, when it agrees with their point of view, and so do not fact check something they say. Sometimes they will say something believing it to be true, but will be mistaken. When this happens it is not a lie.
There is a moral hazard too that there may be incentives in the system to be sloppy and not fact check, if the statement advances your cause. But, normally, we think that active debate solves that. In a world of good faith honest politicians, politicians are still going to make untrue statements not knowing that they are false, but in that world, they will admit that they were wrong when they learn otherwise and are asked about it.
Similarly, immaterial mistakes and statements that no one told them was expected by the person making them to be believed (i.e. satire type statements) are not lies. A misstatement about which state Kansas City is in, shows that you are stupid, not that you are a liar.
Likewise, if you say that the sky is green when it is blue, you are probably engaged in hyperbole and not making a statement that you expect people to treat as a real statement of fact. Often this involves rhetorical exaggeration ("The most important issue facing our community today is . . .).
In the law, opinions are not facts.
Statements of opinion are incapable of being lies, if they are sincere. The only lie you can make about a statement of opinion is saying you believe something when you actually don't.
This kind of lie is often a necessity imposed by civility and the need to interact socially to get things done harmoniously and is only rarely pernicious.
None of this is to say that politicians don't actually flat out lie in the narrow sense.
But, once you cut through the morass of things that are often colloquially called lies, some of which really are inevitable, to actually lies, the issue is a lot less pervasive and clear cut.
Politicians aren't routinely in the business of making statements about presently existing facts period. Most of the time they are making promises and arguments and resolving differences of normative values, although certainly they do sometimes lie to achieve their ends or protect their reputations.
It would be interesting to consider the questioners examples of lies to determine what kind of statements are really the focus of that concern.
Even What Counts As A Lie Has A Partisan/Class Dimension
There is a fair amount of political science research to suggest that there is a big socio-economic class and cultural divide in what people means when they talk about politicians lying.
Upper middle class educated information sector workers like myself, tend to focus on the legalistic definition of a lie.
Many high school educated, working class people outside the information sector of the economy, often don't consider a legally defined lie to be a lie or a serious infraction at all, and instead focus on issues like politicians stating that they care about you, when this seems to be insincere and when politicians who say they care about you don't do what you want them to do.
This and closely related conceptions of what lying by politicians means and when it matters, is much more closely linked to declining trust in institutions than actual untruthfulness in the formal conception of what is is a lie.
For example, when you look at measures of trust of professions and public officials, the best predictor of lack of public trust is that a profession or public official is in the business of negotiating outcomes and deals, rather than simply issuing orders that must be followed (the military always ranks high because that is what it does, politicians, attorneys, and car salesmen always rank low, for the same reasons).