Second-term presidents are often seen as weak, tired, or ineffective. But US President Barack Obama, freshly sworn back into office, seems to be ready to fight for an increasingly progressive agenda.

Aside from his advocacy of equal marriage rights, about to come up in what may be a critical Supreme Court case, and thus out of the president's control, four issues seemed to matter most to Obama: gun control, welfare, climate change, and immigration.

After the mass murder at a Connecticut elementary school in December, the Obama administration put forth a plan for greater regulation of firearms. The plan calls for background checks for all prospective gun buyers, and promises to ban "assault rifles" of the type used in the Sandy Hook killings. Though likely to pass in some form, the administration's proposal will be opposed by conservatives and the gun lobby.

Obama's political challenge will be to win the political support of conservative Democrats and moderate Republicans by keeping the issue in the public consciousness long enough to affect reform.

Nevertheless, he will likely encounter difficulty in legally defining "assault rifles," and a ban on such guns is likely to be dropped from any legislation passed by the US Congress.

Obama has been keen to rebut the attacks on the US social welfare system made by the Republican campaign in last year's presidential election. In the president's words, "The commitments we make to each other - through Medicare, and Medicaid, and Social Security - these things do not sap our initiative; they strengthen us."

Such partisan advocacy for the social safety net put Republican opponents on notice that Obama seems willing to defend entitlement programs while negotiating future budget deals with congress.

Still, the administration will face political pressure from Republican governors who have been slow to enact the president's new healthcare reforms, and from Republican congressmen who want to reduce social security benefits and other entitlements in order to reduce the national debt.

During the presidential campaign, Obama was nearly silent on the issue of environmental policy, because he knew he could take most of the "green" vote from Republican challenger Mitt Romney without difficulty, but might lose support from moderate and undecided voters should he broach the subject.

With no need to worry about future reelection, Obama came out in strong support of the environment in his inaugural speech.

Yet the political waters ahead will be a tricky run for the president. Obama will almost certainly attempt to make some further effort to regulate pollution by using the US Environmental Protection Agency to create and enforce new clean air standards for existing power plants, and to regulate the process of hydraulic fracturing to extract oil and natural gas from the earth.

However, the president's first hazardous stretch will arrive within the next few months, as Obama will have to decide whether or not to approve plans for the Keystone Pipeline, a massive oil delivery project with clear environmental risks.

If the president does approve the project, expect that he will ask congress to consider a new clean energy standard requiring more renewable energy, and perhaps a cap on carbon, something the Democrat-controlled Senate failed to pass during the president's first term.

If Obama does not approve Keystone, further negotiations with congress on environmental issues may not be productive.

Apart from healthcare, Obama's biggest potential success in determining his legacy, and that of the Democratic Party, will be to achieve meaningful reform on immigration.

With overwhelming support in the Latino community, Obama will almost certainly ask congress to pass legislation guaranteeing a "path to citizenship" for the approximately 11 million undocumented workers in the US and their families.

Republicans will be put on the defensive by such a proposal, because they fear the political ramifications of a huge number of newly enfranchised citizens who will likely vote for Democratic candidates.

Yet if they don't concede on the citizenship issue, they will not be able to improve their standing in an expanding community of Latinos citizens already able to vote, further consolidating their demographic disadvantage.

Ultimately, it remains to see if Americans from across a broad political spectrum will follow the guiding light of a suddenly more idealistic president.

The author is a freelance writer and political observer living in Columbus, Ohio. opinion@globaltimes.com.cn