Sen. Mark Udall, D-Colo., raised $1.5 million in the first quarter of 2013 and has $2.5 million in the bank to kick off his re-election campaign in 2014.

On paper, the re-election race should worry Senate Democrats: Colorado is a competitive state, and in recent cycles national parties have dumped millions into races there.

But Udall’s supporters list his strong fundraising as one of the reasons the first-term senator does not top this cycle’s list of the most competitive races. More importantly, Udall has yet to field a serious GOP challenger.

State and national Republicans are still hunting for a challenger, but they continue to express conviction that they will launch a formidable challenge against Udall, CQ Roll Call reported last week.

Udall spokesman Michael Saccone provided the figures to CQ Roll Call for the fundraising period that included the first three months of this year. Candidates are not required to file fundraising reports with the Federal Election Commission until mid-April.