Donald Trump is enjoying a post-convention bounce in the polls after a forceful acceptance speech last week. But that doesn't change an underlying dynamic of the presidential race so far: the Republican nominee is mired in a political rut strikingly similar to Mitt Romney's from four years ago. He has to do more than take the lead in a couple polls to undo that.

At this time in 2012 Romney was trailing President Obama in most polls in the low to mid-single digits, a harbinger of his 51 percent to 47 percent Election Day defeat. Then as now, the economy was voters' top concern, but Romney could not gain an edge on the subject. The exit polls gave him just a one-point advantage over Obama on the question of who would do a better job handling the economy, a question he needed to win handily if he were to oust an incumbent president.

A mobile survey taken before the party conventions of more than 3,000 likely voters by consumer analytics startup InfoScout modeled on the turnout patterns of 2012 found that Hillary Clinton is actually narrowly beating Trump on the economy question. She also wins among the voter groups that check off either unemployment, rising prices, or the housing market as their top economic concern. Trump only won among those who chose taxes as their top economic concern. Why is Trump struggling in territory where he should be excelling?

Put simply, for all his unconventionality, Trump still can't break out of the box that Obama and the Clintons have trapped the GOP in for the last eight years: a party of fat cats that leaves the little guy behind. The narrative stems from the 2008 financial meltdown, an event that turned Obama's fortune from around even odds to overwhelming favorite over John McCain. When asked to give the keynote speech for Obama's reelection, Bill Clinton at the 2012 Democratic National Convention told the nation, "They want to go back to the same old policies that got us into trouble in the first place." It worked.

Hillary Clinton goes even further on Trump than her husband did on Romney. She accuses Trump of being someone who sought to profit off the housing crisis as a real estate developer and who is inclined to cause a repeat of it as president. "He wants to roll back the financial regulations that we have imposed on Wall Street to let them run wild again," she told a Southern California audience recently. Expect her to use more of this rhetoric in her acceptance speech on Thursday night.