Sinn Fein, Ireland’s most popular political party

As of this weekend, Sinn Fein can proclaim themselves to be the most popular political party in Ireland. Discuss.

All-Ireland European Election Results May 2014
Sinn Fein 483,113 – (21.2%)
Fianna Fail 369,545 – (16.2%)
Fine Gael 369,120 – (16.2%)
Independents 328,766 – (14.4%)
DUP 131,163 – (5.7%)
Green Party 92,056 – (4.0%)
Labour 88,229 – (3.9%)
Ulster Unionists 83,438 (3.7%)
SDLP 81,594 (3.6%)
TUV 75,806 (3.3%)
Alliance Party NI 44,432 (1.9%)
Socialist Party 29,953 (1.3%)
UKIP 24,584 (1.1%)
DDI 24,093 (1.1%)
PBP 23,875 (1.0%)
Catholic Dems 13,569 (0.6%)
NI21 10,553 (0.5%)
Fis Nua 4,610 (0.2%)
Conservatives 4,144 (0.2%)