Why the PDs can get more comfort from statistics than opinion polls

IN the recent TNS/MRBI survey, the PDs polled 1%.

In the 2002 election, 76% of the population was eligible to vote (2,994,409), and nearly 63% of those who had a vote used it (1,878,393).

In 2007, projecting the same ratios for the electorate (76%) and turnout (63%), would produce the following outcome: