Colorado’s Republicans put the brakes on the state’s growing Democratic Party affiliation, gaining 789 more active voters than the Dems between July 2014 and July 2015. Democrats increased their active voter base by 16,217, while Republicans increased theirs by 17,006. The 789-voter difference isn’t a big number until compared with the 80,554 increase in voter registration Dems picked up between July 2012 and July 2013.

Both parties, however, are way behind unaffiliateds. Dems lost 68,886 active registrations from July 2013 to July 2015; Republicans lost 39,155. Unaffiliateds dropped the least, at 21,480. Unaffiliateds lead among active voters at 1,034,852 to Democrats at 895,417 and GOPers at 954,495.

Based on previous elections, the rise in unaffiliateds favors Democrats. The 2010 campaign defines the GOP’s problems. Republicans had a 109,111 active-voter advantage over Democrats and a 155,591 active-voter advantage over unaffiliateds. Gov. John Hickenlooper and U.S. Sen. Michael Bennet, both Democrats, won statewide because the Republican candidate field that year, especially for governor, was chaotic and ultimately ineffectual. Unaffiliateds broke heavily to the Democrats, as did some GOPers.

In 2014, Republicans split victories with Democrats. They had a 57,475 active-voter advantage over the Dems and a 61,810 active-voter disadvantage to unaffiliateds. The GOP lost the governor’s race by choosing a weak, establishment candidate, but won the U.S. Senate seat with young, energetic U.S. Rep. Cory Gardner. Incumbent Mark Udall struggled to gin up enthusiasm among Democrats. Even so, the Senate race was tight, with Gardner winning 47.4 percent of ballots cast, edging Udall’s 45.5 percent. To get the results that close, it appears unaffiliateds broke to the Democrats’ side at a substantially higher rate than for Republicans. This has been the Democrats’ advantage.

Unaffiliateds grew at a higher rate than both Democrats and Republicans in 18 of 35 state senate districts between July 2014 and July 2015. Six senate districts grew by over 3,000 voters, with SD14 in Fort Collins gaining the most, at 5,440. The north I-25 and CO-36 corridors added more voters in general, with four of the fastest growing senate districts.

Two Senate races will be hot and close. In SD 19, state Sen. Laura Woods, R-Arvada, faces a rematch with former state Sen. Rachel Zenzinger, D-Arvada. Republicans are up by 756 active registered voters, but Democrats netted 385 new voters between 2014-2015 to the GOP’s 65. With numbers this close and the trend favoring Democrats, Woods will have a tough battle keeping her seat.

The Arapahoe County SD 26 seat held by term-limited state Sen. Linda Newell, D-Littleton, will be an open seat. State Rep. Daniel Kagan, D-Cherry Hills Village, and Arapahoe County Commissioner Nancy Doty will be in a free-for-all there. Dems lead in voter registration by 914 votes and gained 850 new voters to the GOP’s 500 between 2014 and 2015.

Statewide, the GOP has improved its position with active voters. Even so, the state is on a teeter-totter — neither party can keep the other firmly up in the air. Unaffiliateds will provide the tip in either direction.

Paula Noonan owns Colorado Capitol Watch, the state’s premier legislature tracking platform. She’s a declared candidate for one of the Jefferson County School Board seats facing a recall and is a former member of the Jeffco School Board.