Amash has been sitting as an elected official since the age of 28 and that's unlikely to change anytime soon. He'll be a Paul Ryan 10 years down the road and I'd bet my avatar on it.
To be fair, the truth is in the middle.
Rand Paul has not been an elected official long, but he has had a very active political career. He founded one of those anti-tax organizations in the early 90's and regularly campaigned for his father.
Implying that he only recently got into politics is very inaccurate.