DERRY – Republican presidential hopeful John McCain said yesterday younger generations will suffer if politicians don't curb spending in Washington .

During a stop at Pinkerton Academy, the Arizona senator said voters lost confidence in Republicans before the 2006 midterm elections because spending was out of control. He promised to veto any wasteful spending if elected President.

Jo Jensen, 22, of Manchester asked McCain what he would do to fix Social Security for future generations without overburdening young people. Jensen is a member of the grassroots group Students for Saving Social Security.

McCain said politicians must work together to prevent the Social Security system from collapsing. Older Americans aren't at risk of losing their benefits, he said, but younger ones are if the problem isn't fixed.

"You've got to do it in a bipartisan fashion," McCain said.

McCain, who ran unsuccessfully for the party nomination in 2000, also said he would veto unfunded mandates from Congress if he's elected. He said that there are ways of making health care affordable and accessible without converting to a single-payer system.

McCain also reasserted his support for keeping troops in Iraq, holding oppressive governments accountable and reducing climate change in part by using more nuclear power.

Linda Macia of Manchester asked the senator about his stance on medical marijuana. She said she's taken numerous medications for her neurological illness, and only marijuana has been able to ease her pain. Medical marijuana is legal in a dozen states; New Hampshire is not one of them.

"It really makes a difference in pain management," she said, sitting in a wheelchair.

McCain said he trusts the opinions of medical experts who say there are much more effective drugs to kill pain than marijuana. He said he's constantly asked about medical marijuana on the campaign trail and rejected claims that dying patients are being arrested for using the drug.