Read the excerpt from Obama's Second Inaugural Address.

But we have always understood that when times change, so must we; that fidelity to our founding principles requires new responses to new challenges; that preserving our individual freedoms ultimately requires collective action. For the American people can no more meet the demands of today’s world by acting alone than American soldiers could have met the forces of fascism or communism with muskets and militias. No single person can train all the math and science teachers we’ll need to equip our children for the future, or build the roads and networks and research labs that will bring new jobs and businesses to our shores. Now, more than ever, we must do these things together, as one nation and one people.

How is the underlined portion of this excerpt best characterized?

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as evidence