During the presidential campaign last fall, Univision asked President Obama about his biggest failure in his four years in office.

His answer: passing comprehensive immigration reform.

But Obama, at the forum sponsored by the Spanish-language network in September, continued:

"I think that I’ve learned some lessons over the last four years, and the most important lesson I’ve learned is that you can’t change Washington from the inside. You can only change it from the outside. That’s how I got elected, and that’s how the big accomplishments like health care got done."

Mitt Romney and the Republican Party pounced on those comments. "The president today threw in the white flag of surrender again,” Romney argued. “He said he can’t change Washington from inside; he can only change it from outside. Well, we’re going to give him that chance in November. He’s going outside!”

Yet campaign rhetoric aside, Obama was admitting a simple truth about American politics at that Univision forum: The power to change policy comes from public opinion. And it also comes from the ballot box.

In other words, elections have consequences -- especially after more than 70 percent of Latinos backed Obama in the 2012 presidential election, up from 67 percent in 2008.

That explains why Sen. John McCain (R-Ariz.) -- who once championed comprehensive immigration reform but has opposed it ever since the '08 election -- is back on board.

"Elections, elections. The Republican Party is losing the support of our Hispanic citizens," McCain said at a news conference yesterday announcing his support of bipartisan principles to reform the nation's immigration system.

Sen. Chuck Schumer (D-N.Y.) put it another way. "The politics on this issue have been turned upside down," he said. "There is more political risk in opposing immigration reform rather than supporting it."

None of this is to say that immigration reform's passage through Congress is a sure thing. Already, opponents are asking that the Senate slow down consideration of any legislation. "No secret accord with profound consequences for this nation’s future can be rushed through. That means a full committee process and debate and amendments on the floor of the Senate," Sen. Jeff Sessions (R-Ala.) said in a statement yesterday.

But it does point to how outside forces -- and elections -- can change politics, at least for a while, on issues like immigration and taxes.