From obama.senate.gov/issues:

Tax Reform

Our federal tax code has become increasingly complex and unfair. Tax rates should be as low as we can afford them to be; and everyone should pay their fair share. Reform options should focus on creating a system that is simple, progressive, easy to comply with and devoid of abusive shelters. When examining reform options, Senator Obama believes that we should ensure any changes to the tax code reflect the needs and everyday worries facing ordinary Americans, while also promoting America’s competitiveness in the world economy.

Good Government, Responsible Spending

Federal Funding Accountability and Transparency Act Senator Obama worked closely with Senator Coburn, to draft and ultimately pass the Federal Funding Accountability and Transparency Act. President Bush signed this measure into law in September of 2006. This important bill will...

Energy

Senator Obama believes that America must commit to a new national energy policy focused on improvements in technology, investments in renewable fuels such as wind and solar power, and greater efforts in conservation, efficiency, and waste reduction. Shifting from our current investment and consumption practices to this new direction will be one of the great leadership challenges in the coming decade.

Iraq

Since 2002, and now, as a U.S. Senator, Senator Obama has continued to critique the Administration's mishandling of this war, and believes that while our troops have done an outstanding job in Iraq, there can be no military solution to what is inherently a political conflict between Iraq's warring factions. The only hope to end this burgeoning civil war is for Shiites, Sunnis, and Kurds to come together and resolve their differences, and that's why Senator Obama agrees with the Iraq Study Group's conclusion that we must begin a phased redeployment of American troops to signal to the government and people of Iraq that ours is not an open-ended commitment.

Defense

With the nation facing unprecedented threats, it is essential that our military continues to be the best in the world. The Pentagon must adapt to face 21st century threats such as global terrorists and loose nuclear weapons in the former Soviet states. Senator Obama is working to ensure that the nation's defense capabilities are strong, agile, and prepared and that our troops are provided with the equipment they need.

Seniors

As we transition to an increasingly global economy, many Americans are at risk of being left behind through no fault of their own. Among those most affected by these changes are senior citizens, many of whom are on fixed incomes. We need to modernize our social safety net to help senior citizens meet these new challenges, but we also must preserve those elements, such as Social Security and Medicare, that have enabled us to fulfill our moral commitment to our parents and grandparents.

Crime

Senator Obama is a strong proponent of tougher measures to fight crime and provide more resources to local law enforcement officers. He is particularly concerned about the growing problem of methamphetamine, which is ravaging many communities in Illinois.

Environment

As a member of the Senate Environment and Public Works Committee in the 109th Congress, Senator Obama worked to ensure our nation's environmental laws and policies balance America's needs for a healthy, sustainable environment with economic growth. He will continue to push for sound environmental policies with his colleagues in the 110th Congress.

Homeland Security

Senator Obama believes that greater attention needs to be paid to the nation’s homeland security. To that end, he has supported efforts to distribute more funds to cities like Chicago most at risk of a terrorist attack. He has also introduced legislation to strengthen chemical plant and drinking water security and to enhance disaster preparedness.