As if Sen. John McCain's current poverty tour wasn't enough of a clue, his campaign manager Rick Davis made it explicit in a strategy memo yesterday: They see the road to the White House running straight through poor people's pockets.

"Our targeting and analysis of the 2008 political landscape puts voters who are on the lower economic brackets at the heart of either party's winning coalition," Davis said in the memo dissecting exit polling from Tuesday's Democratic primary in Pennsylvania.

Davis' conclusion is that the protracted Democratic race has exposed some serious fault lines, and while he appears to believe Sen. Barack Obama will still be Democrats' nominee, Obama is not very competitive among union households and poor voters. Sen. Hillary Rodham Clinton easily won among both of those demographics in Pennsylvania on Tuesday, reprising the results from Ohio's primary last month.

That matters, of course, because Ohio and Pennsylvania are two of the three states pundits predict will determine the election, along with Florida.

As for how McCain capitalizes on this year's poverty-powered election, that's not exactly clear from Davis's memo. He points out McCain is visiting poor areas and asking for votes, and says McCain next week will lay out a health care plan. But McCain is still in a difficult spot: He's angered enough Republican voters over his career that some won't turn out to vote for him, and he's got to make up ground in the middle. But he can't swing too far back to the old McCain without losing still more Republicans.

As McCain strategist Charlie Black told me for an article today on McCain's domestic brand identity, they've got to try to take conservative principles and prove to voters those principles are a better answer than Democrats' solutions.

That, more than likely, means attacking Democrats repeatedly over taxes and spending.

— Stephen Dinan, national political reporter, The Washington Times