Here the story. It's not just getting information from another nation - it's an illegal quid-pro-quo:
http://thehill.com/blogs/blog-briefing-room/news/376182-watergate-prosecutor-trump-russia-quid-pro-quo-was-about
"What we're dealing with here is a conspiracy to break into the Democratic National Committee, steal emails, and use those emails to help Trump get elected, and the quid-pro-quo for that was the dropping of sanctions," Ackerman told MSNBC's Chris Hayes.
http://thehill.com/blogs/blog-briefing-room/news/376182-watergate-prosecutor-trump-russia-quid-pro-quo-was-about
"What we're dealing with here is a conspiracy to break into the Democratic National Committee, steal emails, and use those emails to help Trump get elected, and the quid-pro-quo for that was the dropping of sanctions," Ackerman told MSNBC's Chris Hayes.