I've knocked around Rand Paul quite a lot over the last year-plus, and I think most or all if it was well-deserved (I've also, it should be noted, praised him a few times as well, when he deserved it). But Paul's decision to drop out of the race today (before New Hampshire) in order to help unify the party to defeat Trump, shows that he, like Scott Walker, is a true Republican who believes in conservative principles, and for that he should be commended.
See, there are two types of people who call themselves Republicans. The first are those who call themselves Republicans because they believe in things like limited government, lower taxes, less government regulations, and the sanctity of human life at all stages of development. The second are those who call themselves Republicans because they perceive that doing so will help elevate them personally or their national profile.
An example of the latter would be Mike Huckabee, who has spent the last two weeks of his campaign living up the rectal canal of Donald Trump, a man whose personal life and politics stand opposed to everything Huckabee has preached for the last three decades. An example of the former would be Scott Walker, who decided not to fight a losing campaign because he understood the need for the party to unify sooner, rather than later, against the existential threat of Trump.
Paul has squarely placed himself in the Scott Walker camp of true Republicans, and rejected the Huckabee camp of career opportunism. Paul knew he was not going to win the nomination, but he had reason to believe that he might have a respectable showing in New Hampshire. Staying in the race for another week would not have measurably hurt his Senate campaign, and he could have gotten himself some free television exposure during this week's debate. Instead, he did the right thing and folded up now, realizing that the best way to stop Trump is for the field for narrow sooner, rather than later.
In this, Rand has shown more maturity and respect for the party than his father, who carried on two pointless campaigns all the way to the convention just to prove a point of some sort. Rand's campaign hasn't been as successful as either of those were, but he's shown himself to be a bigger man, regardless, and for that he can hold his head high.