I just looked at the pipeline sector, saw KMP is down 2.57% for the day, 4.75% for the week but up for the month, while the sector as a whole is down 2.27% today, 5.96% for the week and down a tiny bit for the month. That tells me KMP' performance is comparable with the sector, though it certainly has not been leading it up lately!
Morningstar has zero credibility on MLPs. M* had XTEX(Crosstex) rated 5 stars before it crashed and burned. Their analysis of MLP proved itself fatally flawed and I will never believe anything their say about MLP's.