With the Presidential Election only five months away, expect the rhetoric and mudslinging to escalate. And Forbes‘ Kenneth Fisher has some advice for investors who are getting sucked into the fray: Ignore it.

“This year, ignore political babble,” Fisher writes in his latest Forbes column. “You’ll be better off. Ignore debt debates, silly fake controversies and finger pointing over who is or isn’t the bigger fan of private enterprise. (I win that footrace, anyway.) Or whose supporters are richer or not. And whether that’s bad or not. My forecast is for global stocks to end 2012 up big. Tune out the nonsense, and you’ll better enjoy the ride.”

Fisher says that historically, stocks fare much better in the second half of a President’s term than in the first half, with stocks averaging returns of nearly 11% in the final year of the four-year term. The reason, he says, is that Presidents try to push through their big legislation early in their terms, since they usually lose power after mid-term elections. And investors fear big legislation because it usually results in some sort of redistribution of wealth or rights. “In years three and four, the odds of legislated redistribution lessens, so overall risk aversion lessens — and stocks are more uniformly positive, historically — 86% of all years in the back half,” he writes.

Fisher says there’s another plus this year, when the U.S. will either re-elect a Democrat of elect a new Republican. Historically, stocks have gained 14.5% when the former happens, and 18.8% when the latter occurs.