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"FOX News Sunday" viewers will get to see the first national debate in the Kentucky Senate race between conservative/libertarian Republican Rand Paul and liberal/progressive Democrat Jack Conway.

This race is one of the starkest choices being offered to voters this year - both candidates are favorites of the activist bases of their respective parties and both were propelled through upset primary campaigns by online support from those activists. This is truly a base-versus-base election.

The debate, hosted by FOX News colleague Chris Wallace, comes at the pivotal moment in the race. This is the make-or-break moment for Conway.

Polls have generally shown Paul in the lead, but with some instability in that support. This week, Rasmussen Reports has Paul up 11 points. Last week, Survey USA put the lead at only 2 points. While national Democrats have said publicly that the race is still competitive, Conway has mostly had to rely on the netroots on the left side of the Internet to keep his campaign going.

As one Kentucky Democratic operative told Power Play: "He's had to sing for his supper."

Paul continues to get big money from national Republicans and big help from outside groups like Ed Gillespie and Karl Rove's American Crossroads, Hotline reports that the Democratic National Senatorial Committee has cancelled $292,000 in ad buys for the Bluegrass State next week. The money is badly needed in Connecticut where onetime Senate shoo-in Richard Blumenthal is slipping in the polls.

But, if Conway can get over on Paul during the debate, he might get a real bounce in the polls and, more importantly, get Democrats to risk some cash in the state. They need all the money they can to shore up Blumenthal and Illinois' Alexi Giannoulias and a handful of endangered incumbents in Wisconsin, Washington, Colorado, and California in order to erect a firewall around a Senate majority. But Kentucky media is relatively cheap, and even $750,000 might make a big difference in a close race.

If Conway doesn't impress, though, Democrats will likely move on completely and write-off the idea of what now looks like the party's only potential pickup for the cycle.

With less than 48 hours to go, Conway has a lot on the line.

Chris Stirewalt joined Fox News Channel (FNC) in July of 2010 and serves as digital politics editor based in Washington, D.C.  Additionally, he authors the daily "Fox News First" political news note and hosts "Power Play," a feature video series, on FoxNews.com. Stirewalt makes frequent appearances on the network, including "The Kelly File," "Special Report with Bret Baier," and "Fox News Sunday with Chris Wallace."  He also provides expert political analysis for Fox News coverage of state, congressional and presidential elections.