Some dishes are even better the second time around. Some movies are not. Either statement could be true for the posts within your blog archive. The truth is revealed the moment you understand the difference between posts that are timely, or ones that are timeless.
I published one of my timeless classic blog posts titled, "5 Tips for Using Twitter for Business from my blog formerly known as Make Technology Work. Within moments of my LinkedIn publish, I received likes, profile views and invitations to join individuals networks.
I didn't say that to impress you, but to impress upon you that there is no downside to republishing if it's done for the right reasons. The Writing on LinkedIn discussion group (One of LinkedIn's best) always features discussions about SEO republishing pitfalls. "Will my page-rank take a hit?" is the stated concern. Who cares?
If your community and prospective members find value in one of your classics, you are not a bad dog, you are spot on. Search engines need to deliver valuable search results to grow their ad revenue. As the likes and follows grow, so does your street cred. To build your digital leverage, engage your community with your best stuff.