“The amount of money that could be raised by taxing MLPs differently wouldn’t be a needle mover,” he says. “And the current administration has been vocal about the need for energy independence and infrastructure. We think MLPs achieve both these goals and create jobs.”

The decision by energy company Kinder Morgan this summer to buy out its affiliated MLP businesses will probably create unexpected tax liabilities for the MLP unit holders, and the same would hold true if other general partners decided to make similar moves. “We don’t necessarily think there is a widespread industry read-through at this point,” notes Reid in reference to whether others will follow Kinder’s lead.

Finally, while the fund aims to generate a large portion of distributions as return of capital from the MLPs in its portfolio, payouts returned in that form can vary. In the first quarter of 2014, the fund reported 81.17% of distributions as return of capital and 18.83% as ordinary income. In the second quarter, the return of capital accounted for 39.43% of distributions, ordinary income 55.94% and capital gains 4.63%.

Rising interest rates. Rising rates could hurt high-yielding MLPs, and to some extent energy infrastructure companies, by making fixed-income investments relatively more attractive. But Reid believes that for now, at least, there’s a decent yield buffer.

“Our research indicates that MLP performance historically has not gone negative until the yield spread between the 10-year U.S. Treasury and MLPs falls below 150 basis points,” he says. “The yield of the MLP index is about 290 basis points higher than 10-year Treasurys’ and 80 basis points higher than investment-grade bonds’. That’s in line with the historical average. So at current spreads, we think MLPs still have some room to run.”

Nonetheless, he believes investors may need to modify expectations. “A 15% to 16% annualized return for MLPs over the last 10 years has been pretty impressive,” he says. “No one knows how markets are going to perform, but based on that historical data, we think a reasonable expectation for the next five to 10 years might be about four percentage points lower, based on current buy-in yield plus annual growth in payouts of 5% to 7%. We think that’s still a relatively solid return, especially on a risk-adjusted basis.” But, he adds, interest rates, commodity prices, equity markets and other factors will ultimately influence how MLPs actually perform.