Immigration is the issue that won't go away, and I'd like to weigh in. I think that the current immigration system is fundamentally flawed, and that smart immigration reform will make life better for Americans as a whole.
Our current immigration system spends vast resources protecting the border against the entry of undocumented workers, detaining illegal immigrants, and auditing businesses so that the government can force them to fire illegals. This policy is bad for the country because, simply put, immigration is a good thing for America. Immigrants increase domestic demand (which is the goal of unemployment benefits and other stimulus spending), and they reduce the prices we pay for goods by increasing the labor supply. This also lowers the wages that are paid to workers in the short run, but in the longer run lower wages cause companies to expand, hire more workers, and bid wages at least partly back up. As with many economic policies, there are individuals who are made worse off by immigration (though not as worse off as it may seem, because even workers who get paid less enjoy the benefit of lower prices). Basic economic theory tells us, however, that in this case the gains to the rest of the country outweigh the costs to those individuals (see here and here for more complete arguments). Under current immigration policy, we are spending vast sums of taxpayer money to make ourselves worse off. Obviously, that's not good.
Good immigration reform therefore makes it as easy as possible for immigrants to enter the country. We should be careful to keep out those that pose a threat to national security, but otherwise immigrants should be allowed to enter unhindered. In addition to the gains outlined above, a more open immigration policy makes the country better off by reducing the amount of resources we spend combating illegal immigration. A policy of (nearly) open borders therefore causes us to spend less money and allows immigrants to improve our country. Instead of spending lots of money making ourselves worse off, we'd be spending less money making our country richer and more secure.
I also think that there should be a way for current illegals to become citizens (or at least legal immigrants). They should have to pay a fee that will cover the costs of naturalization and should have to settle unpaid taxes, but otherwise should be unpunished. They have already been here improving our country, and shouldn't be asked to cover the costs of past, flawed policies.