U.S. job growth has slowed considerably in the last few months.

　　The economy added 115,000 jobs in April, according to the Labor Department, and the unemployment rate edged down from 8.2 percent to 8.1 percent.  But economists say part of the improvement in the rate is due to people giving up looking for jobs and leaving the work force.

　　At a high school near Washington Friday, President Obama said more than a million jobs have been created in the last six months, but he acknowledged that more growth is needed.

　　“So that is the good news.  But there are still a lot of folks out of work, which means that we have got to do more," he said.

　　Mitt Romney, the president’s likely Republican opponent in the November, election, called the jobs report “terrible” and “very disappointing.”

　　“The American people are wondering why this recovery isn't happening faster, why it's taking years for the recovery to occur,” he said.

　　The economy is one of the top issues on voters’ minds this election year, and the president has been stressing middle-class issues.

　　Mr. Obama spoke to high school students and their parents in Virginia, one of the states where analysts believe the election is likely to be decided. He returned to a familiar theme, urging Congress to prevent the interest rate on subsidized loans to college students from doubling in July.

　　“In the 21st century, it also means higher education cannot be a luxury.  It is an economic imperative that every American should be able to afford," the president said.

　　Republicans want to pay for the rate freeze by cutting spending on health care.  Democrats want to pay for it by raising taxes.

　　While Mr. Obama’s campaign does not officially begin until Saturday, he has made numerous visits to so-called swing states, concentrated on campaign issues, and sharply criticized his political opponents.

　　“The Republicans in the House just voted to keep giving billions of taxpayer dollars every year to big oil companies raking in record profits," he said.  "They just voted to let millionaires and billionaires keep paying lower tax rates than middle-class workers.  They even voted to give an average tax cut of at least $150,000 to every millionaire in America.  And they want you to pay an extra $1,000 a year for college.”

　　The president marks the official start of his campaign Saturday with rallies in the capitals of two swing states - Columbus, Ohio and Richmond, Virginia.

　　A Washington Post poll released Thursday shows Mr. Obama with a significant (51 percent to 44 percent) lead over Governor Romney in Virginia.  Another poll on Thursday indicates that the two candidates are practically even (Obama 44 percent, Romney 42 percent) in Ohio.