LAS VEGAS, Nev. - After canceling campaign events for three days to oversee the response to the devastating storm, President Obama, back on the trail, told supporters in two key battleground states today that superstorm Sandy serves as a reminder that "when disaster strikes, we see America at its best."

"All the petty differences that consume us in normal times somehow melt away," the president told 4,500 Nevadans at a rally in Las Vegas. "There are no Democrats or Republicans during a storm, just fellow Americans, leaders of different parties working to fix what's broken, neighbors helping neighbors cope with tragedy, communities rallying to rebuild, a spirit that says, In the end we're all in this together, that we rise or fall as one nation."

The storm provided Obama with a chance to showcase bipartisan leadership in the final run-up to the election and to cast himself as a take-charge commander-in-chief.

He spent Wednesday touring damaged areas with Republican New Jersey governor and prominent Romney-backer Chris Christie. In a show of bipartisanship, and a budding political "bromance," the president and Christie have publicly praised the others' preparation for and response to the hurricane.

Today, New York City Mayor Michael Bloomberg endorsed President Obama for a second term, citing climate change and saying Sandy "brought the stakes of Tuesday's presidential election into sharp relief."

"We are awed by the destructive power of nature. We're mourning those who've been lost. And we're - we're going to pledge to those whose lives have been turned upside down that we will not quit until we have given them all the help they need to recover," the president said in Las Vegas.

As he flew here from his first post-Sandy campaign event in Wisconsin, the president called state and local officials responding to the storm from Air Force One.

"The thing that I repeated to them every time that I talk to them is, America will not forget them. We are going to make sure they get everything they need. We're going to cut through the red tape and the bureaucracy," he said.