Political observers have long predicted that the outsized popularity of "America's mayor" could not survive the rigors of a presidential campaign indefinitely. Recent news and the passage of time appear to have made this the week that former New York City Mayor Rudy Giuliani’s (R) poll numbers return to mortal status.

The latest Rasmussen Reports national telephone survey finds that Giuliani’s lead over New York Senator Hillary Clinton (D) has disappeared. The former First Lady has closed the gap and pulled to within a single percentage point, trailing just 48% to 47%. Last month, Giuliani had an eight point lead over Clinton. The month before, it was nine points. In fact, Giuliani had been ahead of Clinton in five straight monthly polls dating back to December.

Two other polls released this week show the same slippage for Giuliani. He lost his lead over Illinois Senator Barack Obama (D) and also lost nine percentage points of support in the race for the GOP Nomination.

This latest survey finds that Giuliani’s favorability ratings have also slipped. Fifty-eight percent (58%) of Likely Voters now have a favorable opinion of him. That’s down from 64% in late March and 71% in December (see tracking history). Still, these numbers must be kept in perspective. While down from stratospheric levels, Giuliani’s numbers remain the highest of any 2008 Presidential candidate.

Opinions about Giuliani are less intense than those concerning Clinton. On balance, springing from his leadership in New York City in the aftermath of the 9/11 attacks, they’re also a bit more positive. For the GOP hopeful, 20% have a Very Favorable opinion while 14% have a Very Unfavorable opinion. Clinton’s numbers are 25% Very Favorable and 37% Very Unfavorable.

Overall, Clinton is viewed favorably by 48%, unfavorably by 50%. An earlier survey found that 46% would definitely vote against Clinton no matter who the GOP nominates. Twenty-eight percent (28%) would definitely vote against Giuliani.

Clinton remains atop the polls among those seeking the Democratic nomination. The Clinton campaign also narrowly collected the most money during the quarter, $26 million. However, while the polls and fundraising confirm her status as frontrunner for the nomination, Obama’s performance has made Clinton a potentially vulnerable frontrunner. Obama, second-ranked in polls of primary voters, raised $25 million and can spend more of that war chest on the primaries than Clinton.

While Giuliani is tied with Obama and Clinton, he holds larger leads over former North Carolina Senator John Edwards, New Mexico Governor Bill Richardson, and Senators Chris Dodd and Joe Biden. His recent woes include a televised interview in which he suggested his wife would be welcome at Cabinet meetings and renewed allegations about a former Giuliani associate, Bernard Kerik.

Rasmussen Reports continuously updates favorability ratings and general election match-ups for all Democratic and Republican candidates. We also maintain ratings for Members of Congress, Other Political Figures, and Journalists.

Rasmussen Reports releases updated polling data on the Republican nominating contest every Tuesday. Results for the Democrats are updated on Mondays.

Crosstabs and Historical data available for Premium Members only.