How Effective is Campaigning?

I’ve read that William McKinley stayed home the entire campaign and gave interviews. Question is how effective such an approach might be in this era?

IOW, suppose a presidential candidate didn’t hold a single campaign rally, but ran the same campaign ads, how much of a difference would this make?

Alternatively, how about if the candidate also didn’t run any campaign ads, and just gave unlimited media interviews (assuming he/she was skilled at this). Could this be done?

[I once read that William Proxmire did no campaigning or advertising of any sort and his entire campaign budget was a few dollars for a filing fee. But that’s a senator in a safe seat.]

Campaign rallies are a kind of advertising, and a pretty cheap form at that. When a candidate makes a rally appearance and speaks to a supportive crowd (and invites media, but doesn’t take questions), that generates many minutes of very positive video. The campaign pays their own logistical costs, but the broadcast of (parts of) that video is all free on the news. And while the news outfits can do their own editing, the overall content is pretty firmly in the campaign’s control, and they can effectively demand time on regional channels by just holding the event in the area they want to target. Interviews are even cheaper, but far riskier.

I’d think this candidate would have three problems:

1 - getting any traction in the early primaries; those primary voters in Iowa and New Hampshire expect to have their butts kissed in person.

2 - getting the media to take you seriously and not treat you like some kind of freak. If nothing else, the TV broadcasters would be annoyed that you weren’t giving them their easy thirty-second to four-minute filler story every day during campaign season.

3 - keeping your staff and volunteers motivated; I think a big part of those events is to hype up the guys who spend all day calling people or knocking on doors, whose work is apparently kind of important.

I assume that any nominee of the Republican or Democratic parties would be taken seriously.

But the truth is that I may have framed my OP poorly, and what I was really driving at was the title of the thread - the examples in the OP were offered up as hypothetical extreme cases.

To use another example, suppose a candidate decided to campaign heavily in State X and less so in State Y. How much of a difference does this really make in the outcome of State X versus State Y?

I got to thinking about this when Mitt Romney decided to move into PA during the last week of the campaign, which didn’t move matters much, if at all. Now, as a practical matter, whatever impact it may have had was blunted by the fact that the Obama campaign began running ads in PA as well, along with sending Bill Clinton out there.

But what I’m wondering about is that perhaps the whole campaigning phenomenon is over-rated by the political insiders and the media, and it has little effect to begin with. (Again, this is separate for campaign rallies and advertising.)