Speculation has reached a fever pitch as both presumptive nominees Donald Trump and Hillary Clinton are finalizing their choices for running mate, NBC News reported.
While a vice presidential pick may not swing an election, it can leave an impression about the judgment of a would-be president or it could address something lacking at the top.
The “vetting” process has become more important since 1972. Former Democratic nominee Sen. George McGovern lost in 49 states after it was revealed that running mate Sen. Thomas Eagleton battled depression and received electroshock therapy.
Most recent picks can be broken down in terms of the value they brought to the candidate at the top, whether that be regional, ideological, a resume filler or someone outside-the-box.
NBC News looks at some of the past VP picks and how they helped shape major party campaigns.