Sen. Rand Paul had counted on building from the grass-roots base of his father, former Rep. Ron Paul, and winning enough support from the Republican mainstream to compete for the party’s 2016 presidential nomination.

Instead, the Kentucky lawmaker is slipping in the polls, lagging in fundraising and losing some of his father’s loyalists over foreign-policy disagreements. Campaign metrics suggest he’s no longer a first-tier candidate after falling behind the front-runners on all those measures.

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