If election-year patterns are any guide, investors can expect solid gains for their 2012 stock portfolios.

Indeed, the Standard & Poor’s 500 index has risen in the final seven months in 13 of the last 15 presidential elections , according to the Stock Trader’s Almanac. And since 1896, the Dow Jones Industrial Average has produced an average 9 percent gain during election years when an incumbent president sought a second term — regardless of the outcome.

But the fortunes of individual sectors will also rise and fall in the years ahead depending on which political party wins the White House in November, since policy decisions impact corporate profits.

That spells opportunity for tactical investors who know where to look.

If Romney Wins

A win for Republican presidential candidate Mitt Romney , for example, would likely bode well for dividend-paying stocks, mainly utilities, telecommunications and consumer staples, says Sam Stovall, chief equity strategist for S&P Capital IQ.

That’s because Romney would hold the dividend tax rate at 15 percent rather than allowing the Bush-era tax cuts to expire, which would push dividend taxes to ordinary income rates.

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