The bitter partisan fights that have been waged for months reappeared Monday after a weekend of reflection following Friday's deadly shooting in Colorado.

David Axelrod, a senior adviser to President Barack Obama's campaign, was the first to break the silence on Twitter.

"Tax returns. Bundlers. Bain. MA records & now key docs from Olympics. When it comes to secrecy, Mitt takes the gold!" Axelrod wrote.

The message directed readers to a report that some records from Romney's tenure as head of the Salt Lake City Olympic games had been destroyed.

With the silence seemingly broken, a few hours later Mitt Romney's campaign resumed their attacks on Obama's handling of the economy, sending a press release highlighting a series of reports detailing America's still-weak economic recovery.

"Millions of middle-class Americans are struggling in the Obama economy and there's no relief in sight," Romney spokeswoman Andrea Saul wrote. "After three and a half years, the results of President Obama's policies are clear: businesses aren't hiring, poverty is climbing, and manufacturing is weakening. Middle-class Americans need a new direction, and a new president who can get our economy back on track."

Friday's shooting at a Colorado movie theater prompted a shift in the political tone, as both Romney and Obama turned previously scheduled rallies into solemn events to express sorrow for the Colorado massacre. Both campaigns canceled later events on Friday and pulled political advertising from the airwaves in Colorado.

On Sunday, Obama's campaign said it would keep ads off the air through Friday, and Romney's team said the ads would remain down "until further notice."