Indianapolis ? Three weeks before the election, Republicans are growing increasingly concerned about John McCain’s ability to mount a comeback, questioning his tactics and even his campaign’s main thrust in a White House race increasingly focused on economic turmoil.

“He has to make the case that he’s different than Bush and better than Obama on the economy,” said former House Speaker Newt Gingrich, one of more than a dozen prominent Republicans who in interviews during the past week expressed concern over the course of McCain’s bid. “If he doesn’t win that case, it’s all over, and it’s going to be a very bad year for Republicans.”

Several Republicans, who spoke on condition of anonymity to avoid angering McCain, said the campaign should have sought to plant doubts about Obama’s associations with 1960s-era radical William Ayers and others months ago, rather than waiting until the campaign’s final weeks. Doing so now, they said, makes the 72-year-old McCain come off as angry, grouchy and desperate, playing into Democrats’ hands.

Rather, these Republicans said, McCain needs to strike a balance in his tone – appearing presidential while also questioning Obama’s readiness to serve and judgment to lead. And, several said McCain should close the campaign on an honorable note.

“He doesn’t need an attack strategy, he needs a comeback strategy,” said Alex Castellanos, a longtime national GOP media consultant who worked for McCain primary rival Mitt Romney.

The unsolicited advice comes as McCain campaign officials are becoming increasingly discouraged. From junior aides to top advisers, the frustration is palpable. Some argue the media isn’t giving McCain a fair shake and are weary of the increasingly problematic environment working against the GOP.