MANCHESTER — President Barack Obama's planned return to New Hampshire on Saturday — his second visit in 10 days — shows the rising importance of the Granite State as a key to the presidential election.

With polls continuing to show a tight race in swing state New Hampshire, Obama will return Oct. 27 for a campaign event in Nashua.

An Obama campaign official said details will be released later this week. It will be Obama's fifth campaign visit and sixth overall visit this year and the 10th visit to New Hampshire of his presidency.

The President was in the state last Thursday, campaigning at Veterans Park in Manchester. He also campaigned Sept. 7 in Portsmouth, Aug. 18 in Windham and Rochester, and June 25 in Durham. He made an official presidential visit to Nashua on March 1. And if the New Hampshire race remains close, as expected, it is possible that Obama will squeeze in yet another visit in the final few days before the election.

Romney's most recent major campaign event in the state was Sept. 7 at Holman Stadium in Nashua after an unscheduled stop in Concord on Sept. 6 to meet with veterans. Previously, he appeared on Aug. 21 at St. Anselm College with running mate Paul Ryan.

Romney has also made private return visits to his home in Wolfeboro.

Ryan returned to the state on Sept. 18 and 29.

A Romney campaign official said Romney will “certainly” campaign in New Hampshire before Election Day. Local Republicans say the Romney campaign is intent, if not fixated, on winning New Hampshire.

The frequent Obama appearances show the President's campaign feels the same way. His visits 10 days apart raise the question of why Romney has not campaigned in the state more frequently lately.

But the Romney official pointed out that “another sign of how serious this campaign is” about New Hampshire is the fact that the campaign went up on Boston television Saturday for the first time, adding to its saturation of the southern New Hampshire market.

Nashua, where Obama will appear, is a key city in that market.

Obama's campaign has been advertising on Boston television for at least a month.

Vice President Joe Biden was most recently in the state on Sept. 22 and 23.

Both campaigns have also sent a steady stream of surrogates to New Hampshire, which is one of 11 battleground, or swing, states up for grabs.

The swing states include Colorado, Florida, Iowa, Michigan, Nevada, North Carolina, Ohio, Pennsylvania, Virginia and Wisconsin, as well as New Hampshire.

Although it has only four electoral votes, New Hampshire is viewed by both campaigns as potentially crucial to winning the election. There are several scenarios in which New Hampshire could, in fact, decide the election. The most recent New Hampshire presidential poll was released last Friday by Public Policy Polling, showing the race in a virtual dead heat.

Romney led, 49 to 48 percent, but the margin of error was 3 percent. The previous PPP presidential poll in the final week of September had Obama leading 51 to 43.5 percent.

Several other recent New Hampshire polls have the race tied or virtually tied within margins of error.

jdistaso@unionleader.com