Stocks are down broadly today after an economic report suggested that domestic manufacturing activity contracted in November, sparking fears of a broader slowdown stemming from uncertainty over the fiscal cliff. The Dow Jones Industrial Average (DJINDICES:^DJI) is currently lower by 34 points, or 0.26%, in mid-afternoon trading.

What's dragging the Dow down?
As I discussed earlier today, there are two issues that appear to be weighing on stocks. First, the Institute for Supply Management released its Purchasing Managers' Index this morning for the month of November. The survey of 18 manufacturing sectors produced a reading of 49.5% -- anything below 50% is indicative of contraction. To get a fuller picture of the results, check out this article, which also links directly to the ISM report.

And second, over the weekend, lobbyists and politicians on both sides of the aisle continued to posture over the fiscal cliff, a series of tax hikes and government spending cuts set to take effect in January if Congress doesn't act.

Treasury Secretary Timothy Geithner appeared on five different Sunday news programs to help deliver the Obama administration's message that any cuts to federal entitlement programs must be accompanied by increases in tax revenue. According to Geithner, the only thing standing in the way of reaching agreement "would be a refusal by Republicans to accept that [tax] rates are going to have to go up on the wealthiest Americans."

Meanwhile, Republican House Leader John Boehner told Fox News on Sunday: "Right now, I would say we're nowhere, period. We're nowhere."

And as a side note, the controversial anti-tax lobbyist and founder of the Americans for Tax Reform, Grover Norquist, made an appearance on NBC's Meet the Press warning that "Tea Party two is going to dwarf Tea Tarty one if Obama pushes us off the cliff." At the end of last month, Warren Buffett chided Norquist in a New York Times opinion piece saying that the purported causal connection between investment decisions and tax rates exists only in Norquist's imagination.

To learn more about the fiscal cliff, I strongly encourage you to check out Morgan Housel's column: "What You Need to Know About the Fiscal Cliff."

The day's best- and worst-performing stocks
Currently, two-thirds of the stocks on the Dow are trading lower. Leading the way down are E. I. Du Pont De Nemours (NYSE:DD) and General Electric (NYSE:GE), off by 1.7% and 1.1%, respectively.

As my colleague Matt Thalman noted earlier today, it was announced last week that DuPont, the nation's most valuable chemical maker, had lied to a federal court and investors about its right to use seed technology developed by Monsanto (NYSE:MON). Internal emails from the company purportedly prove that the company knew it didn't have said right. According to the judge in the case, DuPont "knowingly perpetrated a fraud against the court," and "the public is entitled to a full disclosure of the defendants' fraud." According to Bloomberg Businessweek, the judge will next decide whether to uphold or increase the $1 billion awarded to Monsanto at the conclusion of the underlying jury trial in August.

Headed higher, alternatively, are Cisco Systems (NASDAQ:CSCO) and Merck (NYSE:MRK). Last week, Cisco announced that it will be buying Cariden Technologies, a network solutions company, for $141 million. As my colleague Dan Dzombak noted, this is Cisco's third acquisition in November and its 10th in 2012. And with respect to Merck, the pharmaceutical company announced last week that it's increasing its dividend by 2% a quarter from $0.42 per share to $0.43. In addition, the company alerted investors earlier today that it has started a Phase 2 trial of its pending treatment for Alzheimer's disease.

John Maxfield has no positions in the stocks mentioned above. The Motley Fool owns shares of General Electric Company. Motley Fool newsletter services recommend Monsanto Company. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.