Two new national surveys, one from NBC/WSJ (August 15-18, 1,005 RV, MoE +/-3.1%) and one from CBS News/NY Times (August 15-19, 869 RV) show identical results: Obama's lead over John McCain has been cut in half over the last month, from six points to three points. In both polls, Obama now leads McCain 45 to 42.

CBS News/NY Times
Obama 45 (nc vs. last poll July 31 - August 5)
McCain 42 (+3)
Undecided 10 (-3)

Also of note from the CBS/NYT poll: Obama voters more enthusiastic than McCain voters by a two-to-one margin (48-24), McCain leads Independents by 12 (48 to 36). Obama's favorable rating is a net +7 (39/32) and McCain's is a net +1 (34/33).

NBC News/Wall St. Journal
Obama 45 (-2 vs. last poll July 18-21)
McCain 42 (+1)

Also of note from the NBC/WSJ poll: only 52% of Clinton primary backers say they will vote for Obama, while 21% say they will vote for McCain and 27% are undecided. On a related note, Clinton beat McCain in hypothetical match up by 6 points, 49 to 43. McCain holds comfortable leads on national security, Obama has similar leads on domestic issues. 29% say McCain is running a negative campaign while only 5% say Obama has gone negative.

Overall, Obama's lead in the RCP National Average is 1.2%.