Only if you discount people's ability to think for themselves. Both these candidates had been in the public eye for decades. People decided based on what they've witnessed with their own eyes.
Everyone who you will ask will absolutely say they aren't influenced by advertising, yet the branded products are still successful despite being more expensive.
For example medication, people still are buying Tylenol, Mortin, Aleve despite there being cheaper alternatives that are essentially the same thing: Acetaminophen, Ibuprofen, Naproxen. They will start buying these generics only after they are educated that these things are the same thing.
If you're looking for an insurance company (for a car, life etc) you will tend to chose companies that you heard the name of. You might pick up one that's not familiar (to you) only after you do research or someone else will recommend it to you.
It's same with politics, if you would do research I don't think those campaigns would influence you much, but most people won't have time to do a research.
People tend to stick to a small number of news sources, so these sources only tell one side of a story.
You need as much of the info as possible to think for yourself, and you can be manipulated by what you have witnessed.