If I wanted to destroy America:

I would eliminate food stamps. The poor start starving, and they'll start robbing and killing people with more resources. It won't be the wealthy but the middle class, because the middle class is accessible.

I would retract the Obamacare policy that requires insurance companies to devote 80% of their profits toward patient care, and I would retract the coverage of preexisting conditions. This would ensure more bankruptcies, more destruction of the middle class. Otherwise, I'd keep healthcare exactly as is, because it's doing a fine job of 1)decimating the middle class, and 2) confiscating the wealth of elderly people so it can't be passed down to their offspring (average seniors spend 200k out of pocket in the last years of their lives)

I would also retain Medicare just as it is. The way the current system works, it's like an insurance company that covers only people with fatal, costly diseases (in this case, old age). I certainly wouldn't dilute the risk by expanding Medicare to all-- including low risk young people, who then would not have to spend ludicrous amounts of their income on private insurance. No, keep Medicare expensive.

Go ahead and privatize the post office. It's one of the largest employers in the country, and we can't have that. Plus, once it's privatized, it will further milk that desperate middle class when Fedex and UPS can raise their rates at will. Plus, rural folks won't get any mail at all, further cutting them off from civilization and perhaps even forcing more to move inward to the cities. (Fedex and UPS both use the USPS to deliver to those cities, anyway).

Keep gleefully offshoring jobs, and retain the tax breaks for companies that do so.

Expand the wars we already have. Fight Iran, too. Maybe some countries in Africa. The more the middle class is taxed to benefit the Defense Industry profiteers, the better. The more courageous young people we lose in those Middle Eastern shitholes, the better to dilute the quality of nobility and self-sacrifice in the remaining domestic population. Plus, as an added benefit, we'll keep breeding more resentment among Muslims. Which will lead to my next point--

Open our borders. There is nothing like third world, near-slave wages to dilute the power of the middle class to receive decent living salaries. Also, as a bonus, we can bring in a lot of those Muslim fundies pissed off by our policies abroad, and give them chances to attack us here, which will aid in...

Increasing surveillance. After all, when destroying a country and eradicating the middle class, we can't risk the ruling class suffering blowback or consequences. Soldiers are ultimately loyal to country, and cops can only repress so much on their own. More surveillance of ordinary Americans can lead to some great side effects: 1) neutralize any potential folk heroes/revolutionaries/noble, self-sacrificing people who can reverse the destruction of the country before they can even act, 2) inculcate a mentality of fear and distrust, to cow and render meek the rest of the populace

Naturally, increased surveillance requires laws justifying the destruction of the constitution, and that's going great already. Any whistleblowers who object need to be dealt with speedily and brutally to send a message- and again, Obama is doing this well.

However, the internet also needs to be carefully regulated and cracked down upon. This doesn't have to be a situation like the Chinese firewalls. Those who own major telecom companies are generally part of the ruling class, therefore have incentive to work and in hand with the DHS to control sentiments online. Plus, some crowdsourcing, and some gullible people mobilized by Rush Limbaugh and other mouthpieces can do the rest.

Retain a two-party system, where these two 'opposing' parties continue to agree on the most important issues (open borders, wars, increased debt for the middle class, low tax burden for the wealthy and connected, increased surveillance and drones, more militarization of the police, crackdowns on whistleblowers)-- and disagree only on token issues that matter only to subgroups and a few religious fundies (abortion, gay marriage, etc.)

Keep one party giving lipservice to a religion they don't even follow because that's the surest way to get 30% of the country utterly obedient to any agenda the ruling class wants to promote.

Continue to increase the cost of university so kids can come right out of college so far in debt, they'll accept whatever conditions and slave wages their middle class parents used to find unacceptable. We don't want a middle class, after all-- that's the most critical element to destroying the country. And of course, keep them non-dischargable in bankruptcy. We really, really need this debt to be for life, and passed onto parents in the event of death.

Continue the current work with public schools. The surest way to kill a school is to force every ethnicity in the school to pass a test by a certain percentage, because even if the white and hispanic and asian kids pass, odds are the african american kids won't do well, which will give us a chance to cut funding and further damage the school. Plus, we can then use teachers as a scapegoat. They are one of the few unionized professions that still has any power to retain middle class wages, and we can't have that. We want to destroy the middle class, after all, so let's keep arousing public sentiment against them. As a bonus, if we start adding more vouchers, kids can be redirected to schools run as for-profit entities, or informed by places like the Cato institute, so we can help indoctrinate them further into acceptance and passivity towards the status quo.

Keep up with the affirmative action. It's doing a great job of 1) demoralizing students who get into universities they wouldn't have qualified for, so they can flunk out and get in debt and feel guilty over that, and 2) of hindering capable people of the Caucasian ethnicity from achieving opportunities they otherwise would've had, and 3) of breeding resentment between various ethnic groups, which is a vital component if we are to play the middle and lower classes against each other.

Last but not least, keep using mouth pieces like Rush Limbaugh to smear any actual movement for change as communists or hippies. Failing that, coopt any movement like the Tea Party was coopted: have some billionaire brothers fund an event under the same name as the original organization, get the bought and paid for media to cover only the coopted event, and then gradually pervert its aims to suit your own, thus taking all their momentum and power for yourself.

That's just off the top of my head.