The last time a prevailing party ticket did not the carry the home states of both the presidential and vice-presidential candidate was with Richard Nixon's Republican pickup, for a first term, from 1968. Neither Nixon's home state, which was counted as New York (not California) or running mate Spiro Agnew's home state (Maryland), became likewise Republican pickups. Both states held in the Democratic column for Hubert Humphrey (and Edmund Muskie).
So, we have four decades' worth of presidential elections in which home states carried for winning party tickets. Before that, you have to refer to the year 1940 as the last in which a winning party ticket did not carry both home states: Franklin Roosevelt's, from New York, vice-presidential running mate Henry Wallace's Iowa became a Republican pickup for losing Republican presidential nominee Wendell Wilkie. However, Wilkie, from Indiana, failed to win over the home state, Oregon, of his vice-presidential running mate, Charles McNary. (So, that year's presidential candidates won their home states and their opposition-party's running mates' home states.) Before 1940, you have to look to 1916 as Woodrow Wilson was re-elected, to lower numbers, while he and vice president Thomas Marshall lost their home states, New Jersey and Indiana, to the losing Republican ticket of Charles Evans Hughes (of New York) and Charles Fairbanks (who, like Marshall, also claimed as his home state Indiana).
In these cases of the unusual, much of this had to do with recognized base states for the parties. The 1960s became a transitional period (and so too the 1970s and 1980s) with both parties' base states. So, a 1968 Nixon having failed to win Republican pickups from New York and Maryland was very different from his party's previously established base as those states given, 20 years earlier, they were Republican pickups for Thomas Dewey who failed to flip the presidency to the Republican column, as Democratic president Harry Truman won a full-term victory, in 1948.
It's historically likely that the presidential winner for 2016—be it in a Republican pickup or a Democratic hold—will carry both home states of his/her party's presidential/vice-presidential ticket.
I think it's more correlation than causation.
A few of those elections were 40+ state landslides, which greatly increases the chances of picking up the nominee's seats.
Then you have the times when parties nominate individuals from states the parties are overwhelmingly likely to win (Cheney and Wyoming, Biden and Delaware, Obama and Illinois, etc.)
There was a regional advantage when Democrats nominated Southern Governors, but that was in a different political environment.
If Susanna Martinez fails to swing New Mexico to the Republicans, it doesn't make her a worse running mate than Butch Otter.
Technically, Gephardt would be a weak running mate for Clinton, but it's not because he's from Missouri.
