WASHINGTON (AP) — Pressing their economic arguments, President Barack Obama and challenger Mitt Romney are campaigning in three of the most tightly contested states, looking to build enthusiasm with a public otherwise preoccupied with vacations, the Olympics and the sweltering August heat.

Obama was traveling to Florida and Virginia on Thursday, continuing to draw attention to a Romney tax plan that the president says would force middle-income taxpayers to pay more while giving a tax cut to the wealthy.

Romney was headed to Colorado, where he was to appear with 10 Republican governors, some mentioned as potential running mates, at an event near Aspen.

Their travels come as Congress helped the candidates frame the economic issues Wednesday with partisan votes on tax measures that also underscored Washington's political stalemate. The Republican-controlled House approved an extension of Bush-era tax cuts, just a week after the Democratic-controlled Senate voted in favor of Obama's plan for continuing current tax rates only for households earning less than $250,000 or for individuals under $200,000.

The Obama campaign released a new ad Thursday citing a report by the nonpartisan Tax Policy Center that concluded Romney's tax proposals would result in cuts for the wealthiest Americans and higher bills for everyone else. "He pays less, you pay more," the ad says. The campaign said it will air in New Hampshire, Virginia, North Carolina, Florida, Ohio, Iowa, Colorado and Nevada.

With the tax issue dominating the current debate, Obama was visiting two states that represent the bookends of the national economy. Florida is among the states hardest hit by the housing bust and has an unemployment rate of 8.6 percent, higher than the national average and tied for 39th among the 50 states. Virginia, on the other hand, has the 10th lowest unemployment at 5.6 percent.

Colorado, where Romney was to give a campaign address at a fairgrounds in Golden before joining Republican governors at high school in Basalt, has been struggling with a jobless rate equal to the national average of 8.2 percent. For Romney, the trip west is his first political campaign appearance since returning from an overseas trip heavy on foreign policy.

As if to emphasize the challenge facing the presidential contenders, the Federal Reserve on Wednesday said the U.S. economy was losing strength. The Fed took no new action to boost the economy, but it appeared to signal an inclination to take steps to stimulate job creation if the economic deceleration continued.

The next major marker of economic health comes Friday, when the government announces July hiring and unemployment trends.

Economists forecast that U.S. employers added 100,000 jobs in July. That would be slightly better than the 75,000-a-month average from April through June but still below the healthy 226,000 average in the first three months of the year.