As you may have noticed, a few people in this country have problems with Hillary Clinton. President Trump himself is obsessed with her and tweets about her almost daily. He constantly touts his win over her but at the same time he seems somehow unsure that he beat her in the 2016 election. There may even be a special counsel appointed to look into Clinton's alleged crimes (remember the catchy chant, "Lock her up!"?) Trump hates her so his followers know they hate her, too. That's why when Jimmy Kimmel Live! took to the street to ask Trump supporters if Hillary Clinton should be impeached, they were very passionate in their responses: YES.
These people know how strongly they feel, and they want Hillary impeached. And they're not going to let a little thing like the fact that Hillary Clinton is not actually the president and therefore cannot be impeached get in their way.