Its been a tough couple of days for Ron Paul. With a bump in the polls has come an onslaught of blistering criticism and a closer scrutiny of his record.

Paul is now dealing with daily barbs from his GOP rivals, especially Michele Bachmann, who is accusing Paul's non-interventionist foreign policy as being weak when dealing with the threat of Iran obtaining nuclear weapons.

On Monday, Bachmann directly challenged Paul, calling the potential of him becoming president "dangerous" and charging that he would "wait until the United States had a city taken out by a nuclear weapon."

The comments follow up on a heated exchanged during a recent debate in which Bachmann called Paul's non-confrontational policy on Iran "dangerous."

"With all due respect to Ron Paul, I think I have never heard a more dangerous answer for American security than the one that we just heard from Ron Paul," Bachmann said.

"Iran will take a nuclear weapon, they will use it to wipe our ally Israel off the face of the map and they stated they will use it against the United States of America," she said.

Paul has repeatedly warned that the greatest threat to America is not a nuclear Iran, but overreaction to the perceived threat of Iranian nukes.

GOP rival Rick Perry has also openly criticized Paul for his penchant for earmarks.

"Dr. Paul is still birthing earmarks as we speak," said Perry, who added that Paul "had earmarks over the past two years approaching a half a billion dollars."

And even Newt Gingrich, whom Paul has heavily criticized for serial hypocrisy in two negative ads, is asking Iowans to ask the candidates to "stop the negative campaigning."

"They ought to be ashamed of themselves," said Gingrich, who added that the practice of negative ads "demeans America."

Indeed Paul has moved to frontrunner status in Iowa, where a growing consensus that he could win the Republican Party caucus has his GOP rivals taking shots at his record.

Paul's poll numbers have slowly inched upwards. In the latest ABC News/Washington Post poll, Paul is in third place nationally with 15 percent of the vote.

The prospect of Paul wining Iowa has some long-time GOP operatives up in arms.

"It would make the caucus mostly irrelevant if not entirely irrelevant," said Becky Beach, an Iowa Republican who worked for President George H.W. Bush and his son, President George W. Bush, told Politico.

"It would have a very damaging effect because I don't think he could be elected president and both Iowa and national Republicans wouldn't think he represents the will of the people," Beach said.

According to the latest ABC News/Washington Post poll, just 37 percent of Republican and Republican leaning independents nationally think Paul has the kind of personality and temperament to serve effectively as president and just 42 percent of Republicans think he would pursue policies that most Americans would find acceptable.

ABC News polling also finds that in a potential matchup, President Obama holds a significant lead over Paul.

While ABC News has reported on Paul's outreach effort via a "phone from home" program, commercial advertising in the state, and Paul's numerous visits, some political observers say that Paul's support is built in large part with the support of non-Republicans. And ABC News has found many uncommitted Iowans at heavily attended Paul events.

To Paul's credit, he is working hard to win voters in state.

When asked by ABC News' Jonathan Karl if he's going to win, Paul responded, "Well, I am a candidate and I'm doing pretty well in the polls. I would say you shouldn't be able to rule it out."