There are clear links with availability of ephedrine, yes, but the links are counter-correlated with the availability of the cold pills.

Keep in mind that most any doctor or nurse will tell you for sinus congestion, pseudoephedrine works while phenylephrine is essentially no better than placebo.

From the timeline linked in other comments, it's clear the media and government are indulging in "drug war theater". Every time you hand over a driver's license for decongestant, you are supposed to thank your government for keeping you safe.

From the timeline:

1990s:

The Amezcua cartel in Mexico develops an additional source for ephedrine, buying bulk ephedrine powder overseas from some of the same nine factories (in Germany, Czech Republic, China, and India) from which the American pharmaceutical industry buys their supply of ephedrine/pseudoephedrine for cold medicines. Meth's purity doubles, and a flood of meth spreads eastward from the West Coast. The number of people entering rehab for meth skyrockets.

Robert Pennal, head of the Fresno (Calif.) Methamphetamine Task Force, starts seeing large meth labs in California's Central Valley. Four out of every five hits of meth consumed in the United States are coming from these industrial-scale labs.

"The Amezcua brothers revolutionized the meth trade. They turned it from a small mom-and-pop backyard operation to an industrial-scale production line. They made possible the super lab, which is capable of producing 1,500 times what an ordinary user can make for himself." - Steve Suo, investigative reporter for The Oregonian

This is followed by a bunch of misleading stats, such as "blister packs of pseudoephedrine will be found in 47 percent of seized meth labs". They're calling every mom and pop a lab, and failing to seize the mega labs, but by juking the definitions, they can claim they're closing so many labs. Of the 3 guys in a condo "labs" they find, less than half have any Sudafed in the house.

Meanwhile, as the timeline notes for 2004:

Mexico legally imports 224 tons of pseudoephedrine -- twice as much as they need to make cold medicine. The extra 100 tons is cooked into meth, then smuggled, like other drugs, across the border into the United States. As a result, meth on American streets is as pure as it's ever been.

2005:

The Mexican government admits that drug cartels artificially inflated demand for pseudoephedrine and agrees to reduce imports to a level legitimately needed for cold medicine.

2009:

The Mexican government recognizes there is a huge oversupply of pseudoephedrine coming into the country, and most of it is being diverted to the U.S meth trade.

Then they talk about how that realization turned the mega labs into small labs, and how much less meth there is. But now it's...

2011:

Other states struggling with the problem begin using electronic tracking systems to monitor behind-the-counter sales. Kentucky is the first to use the system and more than two years in, officials say it’s failing to bring rates down.

Imagine that. Despite the best efforts of media sales driven hysteria and government drug war theater, it turns out that preventing Americans from readily purchasing inexpensive sinus medication doesn't stop professionally imported meth.

If the US government can't keep meth out of an ultra max prison, how much freedom do you think you'd have to give up before they can keep it out of your state?