When a candidate for a job announces right off the bat in an interview that they are looking to get your job, would that make the hiring manager think twice about hiring them?
When asked during an interview for a professional position in a state government agency (USA) that I will be supervising to explain what excited him about the position he was applying for, a candidate gave as his primary reason that he wanted my position and this would give him the experience to get that when I left. He had heard that I was interested in moving on (I interviewed but failed to get a promotion recently, but am not actively looking for a change) and looked forward to taking my position when I'm gone.
I'm not surprised that someone is looking a few steps down their career path, but was surprised that he would state it so blatantly and not at least follow it up with something about the actual job he was applying for. I'm not after someone who is looking at this job as a stepping stone.