History on how presidential elections affect stock markets

Even though the U.S. president can't legislate bull markets or veto bears, that hasn't stopped historians from crunching stock returns to determine what impact politics has on stocks.

"The credit crisis has forced both candidates to put the economy at the center of their campaigns," notes Robbert van Batenburg, head of global research at Louis Capital Markets, in a report, "The Final Stretch: Stocks Sensitive to Election Outcome."

Wall Street has been churning out election-related research on stocks and the presidency:

•In "Election 2008," Jeffrey Kleintop, chief strategist for LPL Financial, says stocks tend to perform better in periods of legislative gridlock, when presidential power is offset by the opposition party controlling Congress.