I think the last T20 match between these two teams was competitive. Although Pakistan scored 172 runs but remember West Indies also chased well and ended up in 163 runs. They lost only by 9 runs and it is not a big margin. We cannot say that Pakistan will white wash the series. I think WI will play well in the 3rd T20 and the series may end up 2-1.
Pakistan is in really good T20 form since they started there T20 WC campaign this year. Its not easy for this new WI side to compete with such a strong team. Still there performance in 2nd T20 is very encouraging which will boast there moral for the final T20 and the ODI series coming up next. WI main aim right now will be to avoid white wash.
There is no doubt that Pakistan has been playing very well from the T20 World Cup. Their moral and confidence level can be seen in this series too. In the second match, I think the bowlers were complacent or a little overconfident because of which WI was able to score 163 runs. Still they won the match and I think they will win the third match too.