Washington ? Sen. John Kerry has opened narrow leads in Florida, Michigan, New Hampshire and a handful of other battleground state polls since accepting the Democratic nomination, increasing pressure on President Bush to regain lost ground at the Republican National Convention.

The incumbent hopes to reverse Kerry’s gains by reminding voters of his leadership after the Sept. 11 terrorist attacks, outlining a second-term agenda that includes new domestic policies and questioning Kerry’s qualifications to be commander in chief.

Buoyed by the polls, Kerry’s team is growing confident — maybe too confident for some Democrats. Several supporters worry that rising expectations are setting the party up for disappointment should the race tighten after Bush’s convention, which begins Aug. 30.

“You never want to point to your best poll numbers or your worst poll numbers, because neither hold,” said Democratic strategist Dane Strother.

The Kerry campaign has plenty of positive numbers to cite, including:

• A Quinnipiac University poll showing Kerry and running mate John Edwards with a slight lead in Florida over Bush and Vice President Dick Cheney.
• An Epic-MRA survey suggesting that Michigan is tilting slightly toward Kerry.
• An American Research Group survey showing Kerry-Edwards with small lead in New Hampshire.

Those three states, with a combined 48 electoral votes, were evenly split before last month’s Democratic National Convention in Boston.

In addition, Pennsylvania and Oregon — a combined 28 electoral votes — were evenly split in July, and now the states appear to tilt toward Kerry.

The convention helped him trim Bush’s advantage on national security. In a campaign this close, it doesn’t take much to tilt a state from “tossup” to “lean Kerry.”

And it wouldn’t take much to push them back to tossup.

“After Kerry’s pick of Edwards, the Democrat convention highlighting Kerry, and all the big momentum they were supposed to have, Kerry only leads by a couple of points? This is trouble for him because between their convention and Election Day, challengers always lose ground,” said Bush strategist Matthew Dowd.