The names on Mitt Romney’s vice-presidential list confirm that he is sticking with the bet that his candidacy has rested on: this election will driven almost solely by voters’ feelings about President Obama and the economy.

The names that have been circulated as Romney’s short list, Louisiana Gov. Bobby Jindal, ex-Minnesota Gov. Tim Pawlenty, and Ohio Sen. Rob Portman, are all generally safe choices, likely to please his party’s base but not turn off too many independents or energize Democrats like Sarah Palin did four years ago. All of them have generally conservative records, but none are bold, controversial GOP figures like Wisconsin’s Paul Ryan or New Jersey’s Chris Christie, both of whom are beloved by the Tea Party.

At the same time, none of the leading three are a strong attempt to claim any part of Obama’s base. Florida Sen. Marco Rubio and ex-Secretary of State Condoleezza Rice, both of whom might appeal to minority voters, don’t appear to have been closely considered, and it’s not clear that any woman is a serious contender.

Related: Why conservatives don’t want Condi as VP

Jindal is a minority, but Indian-Americans are a tiny part of the population, and his political record has little appeal to moderates or Democrats.

In short, Romney’s vice presidential pick is likely to get a few days of attention and then recede largely to the political background. Romney is counting on winning this election in a one-on-one contest against Obama.

And the safe vice-presidential pick is part of his more generally cautious approach. Romney has done little to highlight his own policy proposals or announce a grand vision. He has not cast his election as some kind of broader change of direction for the country, as President Obama did four years ago.

Romney’s strategy is in some ways to run out the clock, watching as each month’s jobs report show the economy still flagging and hoping that is enough to turn voters against President Obama. His campaign, even more than most challengers, is profoundly more negative about the incumbent than positive about himself.

Will it work? It could. Despite all of the attention given to the Supreme Court’s health care decision, Romney’s struggles to explain his tenure at Bain and his refusal to release more of his tax returns, the polls have shown little change: President Obama has a narrow lead over Romney, as he did three months ago, but remains under 50 percent.

That closeness is in part what appears to be driving Romney to play it so safe. His policy plans, such as the dramatic overhaul of Medicare that Ryan has called for and Romney backs, and his education proposal that is the first step to national school vouchers, are actually quite bold and controversial and would take away from his focus on the economy if he talked about them. Naming a risky vice-presidential choice, as John McCain did four years ago with Palin, could also backfire, so Romney is avoiding that route as well.

The most unorthodox choice he has made in weeks was his decision to appear in front of the NAACP, an audience in which he had few supporters, attack Obama enough to generate boos there, and then slam his critics at a fundraiser that night.

Related: Romney at the NAACP: I will ‘make things better’ for blacks

But Romney’s cautious approach has in some ways helped inspire the Obama campaign to be the more aggressive one. It is introducing new issues, such as immigration and outsourcing, to put Romney on the defensive. Obama aides are making controversial remarks, such as suggesting Romney committed a “felony,” that will drive cable news cycles. The sitting vice-president Joe Biden is likely to be a much stronger “attack dog” than any of the top three people on Romney’s short list.

Romney’s safe choices increase the chances that this election will be decided by three factors that will only be clear in in the fall: the economic picture, the campaigns’ turnout operations and the three debates in October. A monthly jobs report will be released Nov. 2, only four days before the election. If unemployment rate has increased,  that could help Romney. A declining rate in turn helps the president.

We can’t really tell which campaign is doing a better job turning out voters until Election Day, but what the electorate looks like could be decisive. An older, white electorate, like in 2010, would virtually guarantee a Romney victory, while a 2008-like turnout among blacks and people ages 18-30 would be a boon for Obama.

And the debates are likely the biggest moment for the candidates to woo the estimated 10 percent of voters who are undecided.

Follow Perry Bacon Jr. on Twitter at @perrybaconjr