The Kentucky GOP executive committee voted unanimously to ditch the state's presidential primary for 2016, in favor of a caucus:
http://www.charlotteobserver.com/news/politics-government/article12919427.htmlTo be clear, this would allow Paul to run for both offices simultaneously in the primary. He'd still have to make a choice of which office to run for in the general election. But I don't think he minds that too much. If he were to actually win the GOP presidential nomination, I presume he'd give up on his Senate reelection even if not legally required to.