None of them had a niche.
Graham - How many Republican primary voters do you think base their vote on being a hawk, and of those, how many do you think would be okay with "Grahamnesty?"
Huckabee - Old news, his pandering style was very dated
Santorum - Old news, only got traction in 2012 because he was at the right place at the right time to be flavor of the month against Romney, someone who many Republican primary voters disliked
Perry - Old news, literally a joke candidate best known for forgetting which agency of government he'd abolish
Jindal - Brought nothing to the table, and his name is literally "Piyush Jindal." Need I say more?
One (Jindal) was boring. Another (Graham) had limited appeal and was out of sync with the GOP on a major issue (immigration).
The other three were "Old News". The Dick Nixon of 1968 was "Old News"; how did he overcome that? Let's look at that for a minute:
1. Nixon was "Old News", but he had been "Big News" as well. He had a far more substantial career prior to 1968 than any of these guys had prior to 2016. Nixon (and not Joe McCarthy) was the Republican who turned the GOP into Communist Hunters, by actually investigating and nailing Alger Hiss. Nixon was Ike's VP, and he was VP during a historically significant period, including a period where Ike was incapacitated with a heart attack. Nixon lost the Presidency in 1960 by a hair, and in a manner where some asserted (with some basis) that he had been robbed, and that campaign was being contrasted to the Goldwater debacle of 1964. These other guys were barely up to the level of the 1968 Harold Stassen (who did announce that year).
2. Nixon, adeptly, packaged himself as a "New Nixon".
The Selling of the President 1968 shows memos discussing this strategy. A memo from Nixon's strategist, Harry Treleven, talks about how many of the old negatives associated with Nixon (the "Tricky Dick" image, the reputation for meanness and ruthlessness) had faded away to where Nixon could easily be seen as the most qualified candidate and a man who would level with people). The negative that DID hang on, according to Treleven, was Nixon's image as a "loser", and this was overcome by primary wins. Nixon was familiar enough to people to where a narrative of growth and maturity could be sold to the voters and appear credible.
The retreads who ran after 1968 all had important qualifications. Dole was the leading Senate Republican. Reagan was the heir to Goldwater as leader of the dominant faction of the GOP. Bush was Reagan's VP. McCain was a War Hero who was the consistent frontrunner in 2008 and the only GOP candidate in 2008 who polled well enough to possibly beat either Democrat. Mitt Romney in 2012 was the one candidate who had the total package, and who didn't have the negatives of Gingrich (a nasty adulterer), Santorum (a BIG loser in 2006), and Huckabee (a guy who did have a niche but a niche that was for a VICE Presidential candidate). None of those guys had the gravitas of a Mitt Romney, let alone a Dole, McCain, Bush, Reagan, or Nixon. They needed to catch lightning in a bottle, and the only candidate that has honestly done this in my lifetime was Jimmy Carter in 1976. Had Carter ran second or third, he'd be forgotten today.
