First, Graham is a creature of Washington in a year when Republicans are looking outside the capital. Graham has served in the Congress for 20 years (12 in the Senate and eight in the House). Every other plausible GOP nominee either serves outside of Washington or has been in Congress for just a few years (Ted Cruz, Rand Paul, Marco Rubio).
According to a Pew Research Center poll conducted last year, 51 percent of Republicans would rather their 2016 nominee to be a governor than a member of Congress. That’s up from 2007, when just 32 percent did, and might help explain why McCain — a close friend of Graham’s — was able to capture the GOP nomination in 2008. Even worse for Graham is that just 15 percent of Republicans say being an elected official in Washington for many years makes them more likely to vote for a candidate, while 36 percent say it makes them less likely. In 2007, it was 40 percent more likely and only 18 percent less likely.
Graham, simply put, is the wrong candidate for the current mood of the Republican Party. McCain won in a much different environment.