Republican presidential challenger Mitt Romney has jumped ahead of President Barack Obama in several swing states, according to American polls published Tuesday.

According to a Rasmussen swing state tracking poll of 11 swing states worth 146 electoral college votes that were won in 2008 by Obama (at least 270 electoral votes are needed to win the election), Romney now has a two-point lead over Obama, 49%-47%. The survey is based on data collected over the past week. According to the report, 46% of these swing-state voters are now “certain” they will vote for Romney and will not change their minds. “40% are certain they will vote for the president.”

It was the first time Romney held the lead in swing-state polls since September 19. Rasmussen found that the candidates were tied nationally.

The Realclearpolitics average for the period of September 28-October 8 found Romney ahead by 0.7%, a trend echoed by Pew and Gallup polls. A Rasmussen poll put the two candidates neck and neck.

The Pew Research poll released Monday asserted that “Romney’s strong debate performance erases Obama’s lead,” and found that 66% of registered voters believed Romney won last Wednesday’s debate. Obama and Romney are even at 46% among registered voters (a 9-point bump for the challenger); and perhaps more importantly, Romney now has a 49%-45% edge over the president among likely voters, an improvement of eight points since last month.

Pew also found that Romney supporters enjoy a 15-point advantage in engagement. Romney is edging the president in personal favorability with 50% to the president’s 49%, a 6-point drop for Obama. The report also found the president and Romney in a dead heat in terms of who would help the middle class, while Romney was leading the president 51-48% among women voters (a 9-point improvement for Romney and a 10-point decline for Obama).

Following last week’s debate, a number of polls show Romney leading Obama in key swing states.

Pennsylvania — 20 electoral votes

According to a Sienna Research Institute poll, Romney is within three points of the president, with Obama leading 43% to 40%. “Romney not only has Republican support but now leads in vote-rich areas outside of Philadelphia and also in the central part of the state,” SRI’s director Don Levy said in a press release.

North Carolina — 15 electoral votes

A Gravis Marketing poll showed Romney with an 8.7% lead in North Carolina. The poll had a margin of error of 2.9% and consisted of likely voters.

Ohio — 18 electoral votes

Ohio is showing a statistical tie as an NBC4 local TV station poll found 45% favoring the president and 44% of respondents saying they’ll vote for Romney. The poll had a margin of error of +/- 3.5 %. The Washington Times is reporting that Romney has a slight lead in Ohio, 48-47%, a 9-point improvement for the Republican challenger.

Michigan — 16 electoral votes

The same report cited an FMW poll showing Romney within three points of the president in Michigan, where Obama now leads 49-46%.

Nevada — 6 electoral votes

Rasmussen is reporting a statistical tie in the state of Nevada. The telephone poll surveyed 500 likely voters and had a margin of error of +/- 4.5%

Wisconsin — 10 electoral votes

A Public Policy poll taken October 6 found the president leading by only two points in Wisconsin — 49-47% — a 5-point bump for the challenger who was trailing Obama 52-45% only a few weeks ago.