Voters in Nevada and South Carolina make their choices today in a see-saw US presidential race, with polls showing tight struggles in both states.
In South Carolina, Republicans John McCain and Mike Huckabee are fighting for the lead in a race focused on economic worries, while party rivals Mitt Romney and Fred Thompson are hoping for a surprise in a state which has a history of electing the party's eventual nominee.
Voting ends at midnight Irish time, with results expected soon afterward.
In Nevada, Democratic rivals Barack Obama and Hillary Clinton are in a tight duel complicated by uncertainties about turnout. In 2004, only 9,000 Democrats took part in Nevada's caucuses.
Republicans also vote in Nevada but most candidates have focused their attention on South Carolina. Republican results in Nevada are expected after 8pm Irish time with Democratic results a few hours later.
No one in either party has claimed the role of favourite in the race to pick the two candidates to contest the November 4th election to succeed President George Bush.
A Reuters/C-SPAN/Zogby poll today showed Mr McCain, an Arizona senator, and Mr Huckabee, a Baptist preacher popular among conservative Christians, in a statistical dead heat in South Carolina.
In Nevada, where Democrats hoped an early contest would highlight the party's growing strength in the West, Ms Clinton led Mr Obama by 45 per cent to 39 per cent. Former North Carolina Senator John Edwards was third at 6 per cent.
The Republican contenders head next to Florida for its primary on January 29th, while Democrats primary in South Carolina is next Saturday.
Both parties then turn their attention to the critical February 5th "Super Tuesday" round of 22 state contests.