Denver (CNN) – Ohio Sen. Rob Portman threw cold water on the idea of becoming Mitt Romney's running mate on Wednesday, saying he thinks he'll "end up staying" in the Senate.
"I just got elected two years ago. I think that's where I'm going to end up staying," Portman said when asked his thoughts about possibly leaving the Senate and becoming vice president.
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"I think it's a very important position right now," Portman continued. The senator reasoned there are pressing issues facing the nation - including the debt, the deficit, developing energy resources and health care issues.
Portman then added: "And right now Congress is paralyzed. And we're really in kind of a partisan gridlock. We need leadership, and that's where I intend to stay. I think I can really help in there."
"That's where I think I'll end up being."
Moments before, the senator used similar words, telling a reporter, "We need Mitt Romney. And I will help him all I can. But I'll probably stay in the United States Senate."
It's unclear if Portman is simply keeping the V.P. guessing game going or providing clues to his future plans. It's also possible the senator is not sure who Romney will pick as his running mate – a process being well guarded by the candidate's campaign.
In May, at a Bloomberg View lunch, Portman also seemed to play down his potential as a vice presidential candidate, saying at the time, "I think I'm better suited to stay where I am in the Senate."
Still, Portman's comments are sure to fuel the vice presidential speculation. He's consistently been atop the V.P. list for many political speculators, and is among Romney's staunchest defenders: attending events on behalf of the former Massachusetts governor and praising Romney in various interviews.
Wednesday was no different. The Ohio Republican held forth at five different Romney campaign events in Colorado. Each time the senator ambled off a Romney campaign bus and excitedly praised the candidate while knocking President Barack Obama.
In one tactical move clearly designed to draw attention, Portman visited Denver's Sports Authority Stadium at Mile High – where then-Sen. Obama accepted his party's Democratic presidential nomination in 2008.
With the stadium as a backdrop, the senator mocked the president.
"Where are the Greek columns?" he asked at one point, a reference to the decorative pillars that visually framed Obama during his speech at the 2008 convention. He continued by claiming that the hope and change Obama promised then has not materialized.
Throughout the day's campaign appearances, Portman drew a pointed contrast between Obama, then and now.
Referring to Obama four years ago, Portman said: "[Obama] said…if you don't have fresh ideas he said, you turn to stale tactics and attack your opponent. He said that if you don't have a record to run on, then you make your opponent unacceptable. He said you make a big election about small things."
"That was President Obama four years ago," Portman continued. "Folks, that's exactly what he's doing today in Colorado and in his campaign, negative attack ads, trying to distract people from his record."
Portman also addressed the political topic of the day – an ad from a pro-Obama super PAC that links Romney to the loss of insurance and eventual death of a laid off steel worker's wife.
Obama campaign officials refused to denounce the ad Tuesday and Wednesday, saying the legal separation between campaigns and super PACs meant they had no part in the spot's production.
"I think it's really kind of desperate and frankly kind of pathetic and I also think it's going to backfire on their campaign if they don't come out immediately and say that they reject that ad," Portman said.
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