How deep is America’s political divide between solidly red and solidly blue states?

Forty states have voted for the same party in each of the last three presidential elections — 22 for the Republicans, 18 for the Democrats. In those 18 blue states, the Democratic winning streak is five elections. And while the GOP has gone five for the last five in only 13 states, it has won South Carolina eight times in a row.

So President Barack Obama and former Massachusetts Gov. Mitt Romney understandably will focus much of their campaigns on the relatively few states that are up for grabs.

But before assuming that no Democrat will express admiration for any Republican, or vice versa, review some recent praise for past presidents from the men now seeking the Oval Office.

Mr. Obama has hailed Ronald Reagan as a “transformational president.” Last month, the current president even invoked, though less than persuasively, that conservative icon while pushing for higher taxes on millionaires.

As President Obama put it: “Some years ago, one of my predecessors traveled across the country pushing for the same concept. He gave a speech where he talked about a letter he had received from a wealthy executive who paid lower tax rates than his secretary, and wanted to come to Washington and tell Congress why that was wrong.”

Mr. Obama added: “That wild-eyed, socialist, tax-hiking class warrior was Ronald Reagan.”

Meanwhile, Mr. Romney hailed a former Democratic president Tuesday in Des Moines, Iowa: “Almost a generation ago, Bill Clinton announced that the era of big government was over. Even a former McGovern campaign worker like President Clinton was signaling to his own party that Democrats should no longer try to govern by proposing a new program for every problem.”

And even political novices should suspect that Mr. Romney’s accolades for President Clinton, like President Obama’s for President Reagan, are aimed at winning independent support.

Yet regardless of how many votes are gained — or lost? — in that process, it offers hope that one day a Republican White House nominee will find something nice to say about the Obama presidency.

And who knows? Maybe in the future, a Democratic nominee might even find something nice to say about the George W. Bush presidency.

Well, maybe in the very distant future.