President Obama entered the homestretch of his reelection campaign by laying out a series of goals that he said would build on the successes of his first term and keep the country on a path to prosperity.

But the goals, which touch on issues ranging from education to job creation, vary in their chances of success. The country is already on track to meet some of the benchmarks the president listed, while in other cases, major political and practical hurdles remain in the way.

In a wide-ranging speech at the Democratic National Convention on Thursday, Obama said he would cut oil imports in half by 2020 and develop a 100-year supply of natural gas. He said his administration planned to help companies double their exports, creating a million new manufacturing jobs in four years.

On education, he said he would recruit 100,000 math and science teachers within 10 years. And he expects to cut in half the growth of college tuition in the next decade.

“Our challenges can be met,” he said in his speech. “The path we offer may be harder, but it leads to a better place.”

The remarks drew a rebuke from Obama’s Republican opponent, Mitt Romney.

“It was a whole series of new promises which he also won’t be able to keep because the policies he believes in and the direction he’s pulling will not make America stronger,” he said in a statement.

In reality, some of Obama’s goals will probably be easily met.

Obama pledged to create 1 million manufacturing jobs in the next four years. But if growth in the sector continues at the rate it has shown since the trough of the recession in 2010, that alone will create about 859,000 manufacturing jobs, according to Bureau of Labor Statistics data.

If the recovery speeds up, Obama’s pledge could be accomplished without new federal action.

Current trends also help his pledge to cut oil imports in half by 2020. Daily imports have fallen by nearly a quarter since Obama took office, according to the Energy Information Administration. If imports keep falling by the same amount every year, they’ll be at half of this year’s levels by 2018, two years ahead of Obama’s schedule.

Another of his energy pledges, developing a 100-year supply of natural gas, has already been met, as Obama mentioned in this year’s State of the Union.

Obama’s plan to double exports between 2010 and 2015 will be harder to fulfill. If export growth maintains the rate it has recorded since trade started rebounding in the third quarter of 2009, exports will reach $784 billion at the start of 2015, or a 31 percent increase over 2010, according to data from the Bureau of Economic Analysis. To double by 2015, exports would have to start growing much faster.

Many of Obama’s education goals have been voiced before. In 2010, the President’s Council of Advisors on Science and Technology called for a national effort to recruit and retain teachers in science, technology, engineering and math, noting that out of about 477,000 math and science teachers from kindergarten through high school, about 25,000 leave teaching each year.

In his 2013 budget proposal, Obama sought $1 billion to create a program to retain and mentor teachers. But that requires congressional approval, something that seems unlikely in the current climate. Meanwhile, a coalition of businesses, museums and universities led by the Carnegie Corporation of New York is already working to fulfill his goal.

A new initiative Obama unveiled during his speech was a plan to cut the growth in college tuition by half in the next 10 years. His campaign said he planned to do so by rewarding states that take steps to keep college affordable, by encouraging innovation and by withholding funding from colleges that fail to offer a good value for their education.

But experts say the federal government is limited in its ability to force changes to the system. Although the federal government gives out about $160 billion in student loans and grants, most of that money goes to students. The government has little leverage over the colleges and universities themselves.

In January, Obama proposed making $8 billion in payments to colleges and universities through the Federal Perkins Loan Program, dependent upon an institution’s ability to rein in costs. But that change, too, would require approval from Congress.

Dylan Matthews contributed to this report.