I don't see why UTPD is making such a big deal out of something so relatively unimportant and unsurprising. US Presidents are notorious for lying every now and then, and it happened in most presidencies. Clinton said he "didn't have sexual relations with that woman", Bush said "we don't torture", etc, etc. Its not like this is the first lie a US president ever told, perhaps the most obvious, but hardly the worst (see the one about Iraq having WMDs).
because of all the hay Bill Clinton made out of it in the election in which he was elected.
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http://en.wikipedia.org/wiki/Read_my_lips:_no_new_taxes
"Read my lips: no new taxes" is a now-famous phrase spoken by then presidential candidate George H. W. Bush at the 1988 Republican National Convention as he accepted the nomination on August 18. Written by speechwriter Peggy Noonan, the line was one of the most prominent sound bites from the speech. The pledge not to tax the American people further had been a consistent part of Bush's 1988 election platform, but its prominent inclusion in his speech cemented it in the public consciousness. The impact of the election promise was considerable, and many supporters of Bush believe it helped Bush win the 1988 presidential election.
Once he became president, however, Bush raised taxes as a way to reduce the national budget deficit. Bush refused many times but was making no progress with a Senate and House that was controlled by Democrats. Bush eventually agreed to a compromise with Congressional Democrats to raise several taxes as part of a 1990 budget agreement. This reversal caused great controversy, especially in the more conservative wing of the Republican Party. Although technically there were no new taxes in this agreement, Bush in the same speech also ruled out raising existing taxes. In the 1992 presidential election campaign, Pat Buchanan made extensive use of the phrase in his strong challenge to Bush in the Republican primaries. In the election itself, Democratic nominee Bill Clinton, running as a moderate, also pointed to the quotation as evidence of Bush's untrustworthiness, which contributed to Bush's losing his bid for re-election.