As speculation mounts, Democrat Barack Obama and Republican John McCain are narrowing their choices for vice presidential running mates with their nominating conventions just weeks away. Current and former governors and senators seem the most serious contenders, though most of those mentioned are playing coy about any discussions with either campaign. The choices were expected to carry special weight with voters in this election: McCain would be the oldest person elected to a first term as US president and Obama may be looking for a more experienced running mate since he has just four years on the national political stage. With the Democratic national convention less than a month away, there were growing indications that Sen. Hillary Rodham Clinton – once seen as a natural choice for Obama after he defeated her in an extended primary battle – has been ruled out or slipped to near the bottom of the Illinois senator's short list. Campaign watchers now are looking to Virginia's Democratic Gov. Tim Kaine, who on Tuesday refused to confirm media reports that he has given the Obama campaign his financial records for review. “I'm just not going to talk about my conversations with the campaign,” he said after appearing on a Washington radio station. McCain has likewise kept his decision-making under tight wraps and potential running mates have been just as evasive. Minnesota's Republican Gov. Tim Pawlenty said he has decided to stop answering questions about a spot on McCain's ticket because of all the gossip. Among others believed to be getting close looks were Indiana Sen. Evan Bayh, Delaware Sen. Joe Biden and Kansas Gov. Kathleen Sebelius for Obama; and former Massachusetts Gov. Mitt Romney and former Ohio Rep. Rob Portman for McCain. Obama met Tuesday with top aides and his search committee in Washington for the second time in as many days, and at least the third time this month. He told NBC television on Sunday he was going to pick “somebody with integrity; I'm going to want somebody with independence, who is willing to tell me where he thinks or she thinks I'm wrong; and I'm going to want somebody who shares a vision of the country – where we need to go. That we've got to fundamentally change not only our policies but how our politics works; how business is done in Washington.” That comment casts doubt that Obama would choose Clinton, who has spent more than a decade in Washington as a first lady and New York senator. During the primaries, Obama portrayed her as the ultimate Washington insider while suggesting he offered a fresh approach, above partisanship. Even so, Obama told the network: “I've said consistently that I think Hillary Clinton would be on anybody's short list.” For his part, McCain gave away even less during a Monday interview with CNN television. “I will announce it just as soon as the process is completed,” the Arizona senator said, adding he was vetting both men and women. On the campaign trail, both candidates were focusing on the economy after sparring for most of the last week over the war in Iraq as Obama traveled to the Middle East and Europe.