From highly respected commentator Dennis Prager writing today at Real Clear Politics:
To the extent that I understand how most Republicans think, it would seem that former New York Mayor Rudy Giuliani comes closer to the Republican ideal than any of the other viable Republican candidates. . . when it comes to being strong on both domestic and international issues, it seems that no presently viable Republican candidate matches Rudy Giuliani. . . between Rudy Giuliani (and, for that matter, Mitt Romney) on the one hand and John McCain on the other, there is little question as to who more embodies mainstream conservative and Republican principles. . . In fact, if it is Ronald Reagan that Republicans want, Giuliani is extraordinarily close to that venerated man. Ronald Reagan stood for two great beliefs: that big government is a big problem for a free society and that America must be militarily strong and lead the war against global communism.
Substitute "global jihadism" for "global communism" and you have Rudy Giuliani's twin pillars.